Bridging and IBM Networking Configuration Guide, Cisco IOS Release 15.0SY

Configuring Serial Tunnel and Block Serial Tunnel

This chapter describes how to configure serial tunnel (STUN) and block serial tunnel (BSTUN).

Finding Feature Information

Your software release may not support all the features documented in this module. For the latest feature information and caveats, see the release notes for your platform and software release. To find information about the features documented in this module, and to see a list of the releases in which each feature is supported, see the "Feature Information for Configuring Serial Tunnel and Block Serial Tunnel" section.

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Contents

•Information About Configuring Serial Tunnel and Block Serial Tunnel

•How to Configure Serial Tunnel and Block Serial Tunnel

•Configuration Examples for Serial Tunnel and Block Serial Tunnel

•Additional References

•Feature Information for Configuring Serial Tunnel and Block Serial Tunnel

Information About Configuring Serial Tunnel and Block Serial Tunnel

To configure STUN and BSTUN, you should understand the following concepts:

•Serial Tunnel Overview

•Block Serial Tunneling (BSTUN) Overview

•Asynchronous Network Overview

•Virtual Multidrop Support for Multipoint Security Network Configurations

•Frame Sequencing

Serial Tunnel Overview

Cisco's STUN implementation allows Synchronous Data Link Control (SDLC) protocol devices and High-Level Data Link Control (HDLC) devices to connect to one another through a multiprotocol internetwork rather than through a direct serial link. STUN encapsulates SDLC frames in either the Transmission Control Protocol/Internet Protocol (TCP/IP) or the HDLC protocol. STUN provides a straight passthrough of all SDLC traffic (including control frames, such as Receiver Ready) end-to-end between Systems Network Architecture (SNA) devices.

Cisco's SDLC local acknowledgment provides local termination of the SDLC session so that control frames no longer travel the WAN backbone networks. This means end nodes do not time out, and a loss of sessions does not occur. You can configure your network with STUN, or with STUN and SDLC local acknowledgment. To enable SDLC local acknowledgment, the Cisco IOS software must first be enabled for STUN and routers must be configured to appear on the network as primary or secondary SDLC nodes. TCP/IP encapsulation must be enabled. Cisco's SDLC Transport feature also provides priority queueing for TCP encapsulated frames.

Cisco's BSTUN implementation enables Cisco series 2500, 4000, 4500, 4700, and 7200 series routers to support devices that use the Binary Synchronous Communications (Bisync) data-link protocol and asynchronous security protocols that include Adplex, ADT Security Systems, Inc., Diebold, and asynchronous generic traffic. BSTUN implementation is also supported on the 4T network interface module (NIM) on the Cisco router 4000 and 4500 series. Our support of the Bisync protocol enables enterprises to transport Bisync traffic and SNA multiprotocol traffic over the same network.

Block Serial Tunneling (BSTUN) Overview

Cisco's implementation of BSTUN provides the following features:

•Encapsulates Bisync, Adplex, ADT Security Systems, Inc., Diebold, and asynchronous generic traffic for transfer over router links. The tunneling of asynchronous security protocols (ASP) feature enables your Cisco 2500, 3600, 4000, 4500, or 7200 series router to support devices that use the following asynchronous security protocols:

–adplex

–adt-poll-select

–adt-vari-poll

–diebold

–async-generic

–mdi

•Provides a tunnel mechanism for BSTUN over Frame Relay, without using TCP/IP encapsulation.

•Supports Bisync devices and host applications without modification.

•Uses standard synchronous serial interfaces on Cisco 2500 series and the 4T network interface module (NIM) on the Cisco 4000 series and Cisco 4500 series.

•Supports point-to-point, multidrop, and virtual multidrop configuration.

Note The async-generic item is not a protocol name. It is a command keyword used to indicate generic support of other asynchronous security protocols that are not explicitly supported.

Bisync Network Overview

The Bisync feature enables Cisco 2500, 3600, 4000, 4500, 4700, and 7200 series routers to support devices that use the Bisync data-link protocol. This protocol enables enterprises to transport Bisync traffic over the same network that supports their SNA and multiprotocol traffic, eliminating the need for separate Bisync facilities.

At the access router, traffic from the attached Bisync device is encapsulated in IP. The Bisync traffic can then be routed across arbitrary media to the host site where another router supporting Bisync will remove the IP encapsulation headers and present the Bisync traffic to the Bisync host or controller over a serial connection. HDLC can be used as an alternative encapsulation method for point-to-point links. Figure 1 shows how you can reconfigure an existing Bisync link between two devices and provide the same logical link without any changes to the existing Bisync devices.

Figure 1 Routers Consolidating Bisync Traffic by Encapsulation in IP or HDLC

The routers transport all Bisync blocks between the two devices in pass-through mode using BSTUN as encapsulation. BSTUN uses the same encapsulation architecture as STUN, but is implemented on an independent tunnel.

Point-to-Point and Multidrop Support

The Bisync feature supports point-to-point, multidrop, and virtual multidrop Bisync configurations.

In point-to-point operation, the Bisync blocks between the two point-to-point devices are received and forwarded transparently by the Cisco IOS software. The contention to acquire the line is handled by the devices themselves.

Cisco's Bisync multipoint operation is provided as a logical multipoint configuration. Figure 2 shows how a multipoint Bisync link is reconfigured using Cisco routers. Router A is configured as Bisync secondary. It monitors the address field of the polling or selection block and uses this address information to put into the BSTUN frame for BSTUN to deliver to the correct destination router. To simulate the Bisync multidrop, an EOT block is sent by the Bisync primary router before a poll or selection block. This ensures that Bisync tributary stations are in control mode before being polled or selected.

Figure 2 Multipoint Bisync Link Reconfigured Using Routers

Multidrop configurations are common in Bisync networks where up to 8 or 10 Bisync devices are frequently connected to a Bisync controller port over a single low-speed link. Bisync devices from different physical locations in the network appear as a single multidrop line to the Bisync host or controller. Figure 3 illustrates a multidrop Bisync configuration before and after implementing routers.

Figure 3 Integrating Bisync Devices over a Multiprotocol Network

Asynchronous Network Overview

These protocols enable enterprises to transport polled asynchronous traffic over the same network that supports their SNA and multiprotocol traffic, eliminating the need for separate facilities. Figure 4 shows how you can reconfigure an existing asynchronous link between two security devices and provide the same logical link without any changes to the existing devices.

Figure 4 Routers Consolidate Polled Asynchronous Traffic Using Encapsulation in IP or HDLC

Router A is configured as the secondary end of the BSTUN asynchronous link and is attached to the security control station; Router B is configured as the primary end of the BSTUN asynchronous link and has one or more alarm panels attached to it.

At the downstream router, traffic from the attached alarm panels is encapsulated in IP. The asynchronous (alarm) traffic can be routed across arbitrary media to the host site where the upstream router supporting these protocols removes the IP encapsulation headers and presents the original traffic to the security control station over a serial connection. High-Level Data Link Control (HDLC) can be used as an alternative encapsulation method for point-to-point links.

The routers transport all asynchronous (alarm) blocks between the two devices in passthrough mode using BSTUN for encapsulation. BSTUN uses the same encapsulation architecture as STUN, but is implemented on an independent tunnel. As each asynchronous frame is received from the line, a BSTUN header is added to create a BSTUN frame, and then BSTUN is used to deliver the frame to the correct destination router.

The Cisco routers do not perform any local acknowledgment or cyclic redundancy check (CRC) calculations on the asynchronous alarm blocks. The two end devices are responsible for error recovery in the asynchronous alarm protocol.

Virtual Multidrop Support for Multipoint Security Network Configurations

Multipoint configurations are common in security networks, where a number of alarm panels are frequently connected to a security control station over a single low-speed link. Our virtual multidrop support allows alarm panels from different physical locations in the network to appear as a single multidrop line to the security control station. Both Adplex and ADT are virtual multidropped protocols.

Multidrop operation is provided as a logical multipoint configuration. Figure 5 shows how a multipoint security network is reconfigured using Cisco routers. Router A is configured as an alarm secondary node, routers B and C are configured as alarm primary nodes. Router A monitors the address field of the polling or selection block and puts this address information in the BSTUN frame so BSTUN can deliver the frame to the correct downstream node.

Figure 5 Multipoint Asynchronous Security Protocol Link Reconfigured Using Routers

Frame Sequencing

Both Bisync and asynchronous alarm protocols are half-duplex protocols; data can be sent in either direction, but only in one direction at a time. Each block sent is acknowledged explicitly by the remote end. To avoid the problem associated with simultaneous sending of data, there is an implicit role of primary and secondary station.

Frame Sequencing in Bisync Networks

In a multidrop setup in Bisync networks, the Bisync control station is primary and the tributary stations are secondary. In a point-to-point configuration, the primary role is assumed by the Bisync device that has successfully acquired the line for sending data through the ENQ bidding sequence. The primary role stays with this station until it sends EOT.

To protect against occasional network latency, which causes the primary station to time out and resend the block before the Bisync block sent by the secondary is received, the control byte of the encapsulating frame is used as a sequence number. This sequence number is controlled and monitored by the primary Bisync router. This allows the primary Bisync router to detect and discard "late" Bisync blocks sent by the secondary router and ensure integrity of the Bisync link.

Note Frame sequencing is implemented in passthrough mode only.

Frame Sequencing in Asynchronous Networks

Network delays in asynchronous networks make it possible for a frame to arrive "late," meaning that the poll-cycling mechanism at the security control station has already moved on to poll the next alarm panel in sequence when it receives the poll response from the previous alarm panel.

To protect against this situation, routers configured for adplex or for adt-poll-select protocols use a sequence number built into the encapsulating frame to detect and discard late frames. The "upstream" router (connected to the security control station) inserts a frame sequence number into the protocol header, which is shipped through the BSTUN tunnel and bounced back by the "downstream" router (connected to the alarm panel). The upstream router maintains a frame-sequence count for the line, and checks the incoming frame-sequence number from the downstream router. If the two frame-sequence numbers do not agree, the frame is considered late (out of sequence) and is discarded.

Because the adt-vari-poll option allows the sending of unsolicited messages from the alarm panel, frame sequencing is not supported for this protocol.

Note Polled asynchronous (alarm) protocols are implemented only in passthrough mode. There is no support for local acknowledgment.

How to Configure Serial Tunnel and Block Serial Tunnel

To configure and monitor STUN or STUN local acknowledgment, perform the tasks in the following sections:

•Enabling STUN

•Specifying STUN Protocol Group

•Enabling STUN Keepalive

•Enabling STUN Remote Keepalive

•Enabling STUN Quick-Response

•Enabling STUN Interfaces

•Configuring SDLC Broadcast

•Establishing the Frame Encapsulation Method

•Configuring STUN with Multilink Transmission Groups

•Setting Up STUN Traffic Priorities

The Bisync feature is configured similar to SDLC STUN, but is configured as a protocol within a BSTUN feature. To configure and monitor Bisync with BSTUN, perform the tasks in the following sections:

•Enabling BSTUN

•Defining the Protocol Group

•Enabling BSTUN Keepalive

•Enabling BSTUN Remote Keepalive

•Enabling Frame Relay Encapsulation

•Defining Mapping Between BSTUN and DLCI

•Configuring BSTUN on the Serial Interface

•Placing a Serial Interface in a BSTUN Group

•Specifying How Frames Are Forwarded

•Setting Up BSTUN Traffic Priorities

•Configuring Protocol Group Options on a Serial Interface

•Configuring Direct Serial Encapsulation for Passthrough Peers

•Configuring Local Acknowledgment Peers

Enabling STUN

To enable STUN, use the following command in global configuration mode:

When configuring redundant links, ensure that the STUN peer names you choose on each router are the IP addresses of the most stable interfaces on each device, such as a loopback or Ethernet interface. See the "Configuration Examples for Serial Tunnel and Block Serial Tunnel" section.

You must also configure SDLC address FF on Router A for each of the STUN peers. To do so, use the following command in interface configuration mode:

Specifying STUN Protocol Group

Place each STUN interface in a group that defines the ISO 3309-compliant framed protocol running on that link. Packets will only travel between STUN interfaces that are in the same protocol group.

There are three predefined STUN protocols:

•Basic

•SDLC

•SDLC transmission group (TG)

You can also specify a custom STUN protocol.

To specify STUN protocols, you must perform the tasks in the following sections:

•Specifying a Basic STUN Group

•Specifying an SDLC Group

•Specifying an SDLC Transmission Group

•Creating and Specifying a Custom STUN Protocol

If you want to use the STUN Local Acknowledgment feature, you must specify either the SDLC protocol or the SDLC TG protocol.

Note Before you can specify a custom protocol, you must first define the protocol; see the "Creating and Specifying a Custom STUN Protocol" section for the procedure.

Specifying a Basic STUN Group

The basic STUN protocol does not depend on the details of serial protocol addressing and is used when addressing is not important. Use this when your goal is to replace one or more sets of point-to-point (not multidrop) serial links by using a protocol other than SDLC. Use the following command in global configuration mode:

Specifying an SDLC Group

You can specify SDLC protocol groups to associate interfaces with the SDLC protocol. Use the SDLC STUN protocol to place the routers in the midst of either point-to-point or multipoint (multidrop) SDLC links. To define an SDLC protocol group, enter the following command in global configuration mode:

If you specify an SDLC protocol group, you cannot specify the stun route all command on any interface of that group.

For an example of how to configure an SDLC protocol group, see the "Serial Link Address Prioritization Using STUN TCP/IP Encapsulation Example" section on page 17.

Specifying an SDLC Transmission Group

An SNA TG is a set of lines providing parallel links to the same pair of SNA front-end-processor (FEP) devices. This provides redundancy of paths for fault tolerance and load sharing. To define an SDLC TG, use the following command in global configuration mode:

All STUN connections in a TG must connect to the same IP address and use the SDLC local acknowledgment feature.

Creating and Specifying a Custom STUN Protocol

To define a custom protocol and tie STUN groups to the new protocol, use the following commands in global configuration mode:

Enabling STUN Keepalive

To define the number of times to attempt a peer connection before declaring the peer connection to be down, use the following command in global configuration mode:

Enabling STUN Remote Keepalive

To enable detection of the loss of a peer, use the following command in global configuration mode:

Enabling STUN Quick-Response

You can enable STUN quick-response, which improves network performance when used with local acknowledgment. When STUN quick-response is used with local acknowledgment, the router responds to an exchange identification (XID) or a Set Normal Response Mode (SNRM) request with a Disconnect Mode (DM) response when the device is not in the CONNECT state. The request is then passed to the remote router and, if the device responds, the reply is cached. The next time the device is sent an XID or SNRM, the router replies with the cached DM response.

Note Using STUN quick-response avoids an AS/400 line reset problem by eliminating the Non-Productive Receive Timer (NPR) expiration in the AS/400. With STUN quick-response enabled, the AS/400 receives a response from the polled device, even when the device is down. If the device does not respond to the forwarded request, the router continues to respond with the cached DM response.

To enable STUN quick-response, use the following command in global configuration mode:

Enabling STUN Interfaces

Caution When STUN encapsulation is enabled or disabled on an RSP platform, the memory reallocates memory pools (recarve) and the interface shuts down and restarts. The recarve is caused by the change from STUN to another protocol, which results in a change in the MTU size. No user configuration is required.

You must enable STUN on serial interfaces and place these interfaces in the protocol groups you have defined. To enable STUN on an interface and to place the interface in a STUN group, use the following commands in interface configuration mode:

When a given serial link is configured for the STUN function, it is no longer a shared multiprotocol link. All traffic that arrives on the link will be transported to the corresponding peer as determined by the current STUN configuration.

Configuring SDLC Broadcast

The SDLC broadcast feature allows SDLC broadcast address FF to be replicated for each of the STUN peers, so that each of the end stations receives the broadcast frame. For example, in Figure 6, the FEP views the end stations 1, 2, and 3 as if they are on an SDLC multidrop link. Any broadcast frame sent from the FEP to Router A is duplicated and sent to each of the downstream routers (B and C).

Figure 6 SDLC Broadcast across Virtual Multidrop Lines

To enable SDLC broadcast, use the following command in interface configuration mode:

Only enable SDLC broadcast on the device that is configured to be the secondary station on the SDLC link (Router A in Figure 6).

Establishing the Frame Encapsulation Method

To allow SDLC frames to travel across a multimedia, multiprotocol network, you must encapsulate them using one of the methods in the following sections:

•Configuring HDLC Encapsulation without Local Acknowledgment

•Configuring TCP Encapsulation without Local Acknowledgment

•Configuring TCP Encapsulation with SDLC Local Acknowledgment and Priority Queueing

•Configuring Local Acknowledgment for Direct Frame Relay Connectivity

Configuring HDLC Encapsulation without Local Acknowledgment

You can encapsulate SDLC or HDLC frames using the HDLC protocol. The outgoing serial link can still be used for other kinds of traffic. The frame is not TCP encapsulated. To configure HDLC encapsulation, use one of the following commands in interface configuration mode, as needed:

Use the no forms of these commands to disable HDLC encapsulation.

Note You can forward all traffic only when you are using basic STUN protocol groups.

Configuring TCP Encapsulation without Local Acknowledgment

If you do not want to use SDLC local acknowledgment and only need to forward all SDLC frames encapsulated in TCP, use the following commands in interface configuration mode:

Use the no form of these commands to disable forwarding of all TCP traffic.

This configuration is typically used when two routers can be connected via an IP network as opposed to a point-to-point link.

Configuring TCP Encapsulation with SDLC Local Acknowledgment and Priority Queueing

You configure SDLC local acknowledgment using TCP encapsulation. When you configure SDLC local acknowledgment, you also have the option to enable support for priority queueing.

Note To enable SDLC local acknowledgment, you must specify an SDLC or SDLC TG.

SDLC local acknowledgment provides local termination of the SDLC session so that control frames no longer travel the WAN backbone networks. This means that time-outs are less likely to occur.

Figure 7 illustrates an SDLC session. IBM 1, using a serial link, can communicate with IBM 2 on a different serial link separated by a wide-area backbone network. Frames are transported between Router A and Router B using STUN, but the SDLC session between IBM 1 and IBM 2 is still end-to-end. Every frame generated by IBM 1 traverses the backbone network to IBM 2, which, upon receipt of the frame, acknowledges it.

Figure 7 SDLC Session Without Local Acknowledgment

With SDLC local acknowledgment, the SDLC session between the two end nodes is not end-to-end, but instead terminates at the two local routers, as shown in Figure 8. The SDLC session with IBM 1 ends at Router A, and the SDLC session with IBM 2 ends at Router B. Both Router A and Router B execute the full SDLC protocol as part of SDLC Local Acknowledgment. Router A acknowledges frames received from IBM 1. The node IBM 1 treats the acknowledgments it receives as if they are from IBM 2. Similarly, Router B acknowledges frames received from IBM 2. The node IBM 2 treats the acknowledgments it receives as if they are from IBM 1.

Figure 8 SDLC Session with Local Acknowledgment

To configure TCP encapsulation with SDLC local acknowledgment and priority queueing, perform the tasks in the following sections:

•Assigning the Router an SDLC Primary or Secondary Role

•Enabling the SDLC Local Acknowledgment Feature

•Establishing Priority Queueing Levels

Assigning the Router an SDLC Primary or Secondary Role

To establish local acknowledgment, the router must play the role of an SDLC primary or secondary node. Primary nodes poll secondary nodes in a predetermined order. Secondaries then send outgoing data, if they have any outgoing data.

For example, in an IBM environment, an FEP is the primary station and cluster controllers are secondary stations. If the router is connected to an FEP, the router should appear as a cluster controller and must be assigned the role of a secondary SDLC node. If the router is connected to a cluster controller, the router should appear as an FEP and must be assigned the role of a primary SDLC node. Devices connected to SDLC primary end-stations must play the role of an SDLC secondary and routers attached to SDLC secondary end stations must play the role of an SDLC primary station.

To assign the router a primary or secondary role, use one of the following commands in interface configuration mode, as needed:

Enabling the SDLC Local Acknowledgment Feature

To enable SDLC local acknowledgment, use the following command in interface configuration mode:

The stun route address 1 tcp local-ack priority tcp-queue-max interface configuration command enables local acknowledgment and TCP encapsulation. Both options are required to use TGs. You should specify the SDLC address with the echo bit turned off for TG interfaces. The SDLC broadcast address 0xFF is routed automatically for TG interfaces. The priority keyword creates multiple TCP sessions for this route. The tcp-queue-max keyword sets the maximum size of the outbound TCP queue for the SDLC. The default TCP queue size is 100. The value for hold-queue in should be greater than the value for tcp-queue-max.

You can use the priority keyword (to set up the four levels of priorities to be used for TCP encapsulated frames) at the same time you enable local acknowledgment. The priority keyword is described in the following section. Use the no form of this command to disable SDLC Local Acknowledgment. For an example of how to enable local acknowledgment, see the "Example: Serial Link Address Prioritization Using STUN TCP/IP Encapsulation" section.

Establishing Priority Queueing Levels

With SDLC local acknowledgment enabled, you can establish priority levels used in priority queueing for serial interfaces. The priority levels are as follows:

•Low

•Medium

•Normal

•High

To set the priority queueing level, use the following command in interface configuration mode:

Use the no form of this command to disable priority settings. For an example of how to establish priority queueing levels, see the "Example: Serial Link Address Prioritization Using STUN TCP/IP Encapsulation" section.

Configuring Local Acknowledgment for Direct Frame Relay Connectivity

To implement STUN with local acknowledgment using direct Frame Relay encapsulation, use the following command in interface configuration mode:

Configuring STUN with Multilink Transmission Groups

You can configure multilink SDLC TGs across STUN connections between IBM communications controllers such as IBM 37x5s. Multilink TGs allow you to collapse multiple WAN leased lines into one leased line.

SDLC multilink TGs provide the following features:

•Network Control Program (NCP) SDLC address allowances, including echo and broadcast addressing.

•Remote NCP load sequence. After a SIM/RIM exchange but before a SNRM/UA exchange, NCPs send numbered I-frames. During this period, I-frames are not locally acknowledged, but instead are passed through. After the SNRM/UA exchange, local acknowledgment occurs.

•Rerouting of I-frames sent by the Cisco IOS software to the NCP if a link is lost in a multilink TG.

•Flow control rate tuning causes a sending NCP to "feel" WAN congestion and hold frames that would otherwise be held by the Cisco IOS software waiting to be sent on the WAN. This allows the NCP to perform its class-of-service algorithm more efficiently based on a greater knowledge of network congestion.

STUN connections that are part of a TG must have local acknowledgment enabled. Local acknowledgment keeps SDLC poll traffic off the WAN and reduces store-and-forward delays through the router. It also might minimize the number of NCP timers that expire due to network delay. Also, these STUN connections must go to the same IP address. This is because SNA TGs are parallel links between the same pair of IBM communications controllers.

Design Recommendations

This section provides some recommendations that are useful in configuring SDLC multilink TGs.

The bandwidth of the WAN should be larger than or equal to the aggregate bandwidth of all serial lines to avoid excessive flow control and to ensure response timed does not degrade. If other protocols are also using the WAN, ensure that the WAN bandwidth is significantly greater than the aggregate SNA serial line bandwidth to ensure that the SNA traffic does not monopolize the WAN.

When you use a combination of routed TGs and directly connected NCP TGs, you need to plan the configuration carefully to ensure that SNA sessions do not stop unexpectedly. Assuming that hardware reliability is not an issue, single-link routed TGs are as reliable as direct NCP-to-NCP single-link TGs. This is true because neither the NCP nor the Cisco IOS software can reroute I-frames when a TG has only one link. Additionally, a multilink TG directed between NCPs and a multilink TG through a router are equally reliable. Both can perform rerouting.

However, you might run into problems if you have a configuration in which two NCPs are directly connected (via one or more TG links) and one link in the TG is routed. The NCPs treat this as a multilink TG. However, the Cisco IOS software views the TG as a single-link TG.

A problem can arise in the following situation: Assume that an I-frame is being sent from NCP A (connected to router A) to NCP B (connected to router B) and that all SDLC links are currently active. Router A acknowledges the I-frame sent from NCP A and sends it over the WAN. If, before the I-frame reaches Router B, the SDLC link between router B and NCP B goes down, Router B attempts to reroute the I-frame on another link in the TG when it receives the I-frame. However, because this is a single-link TG, there are no other routes, and Router B drops the I-frame. NCP B never receives this I-frame because Router A acknowledges its receipt, and NCP A marks it as sent and deletes it. NCP B detects a gap in the TG sequence numbers and waits to receive the missing I-frame. NCP B waits forever for this I-frame, and does not send or receive any other frames. NCP B is technically not operational and all SNA sessions through NCP B are lost.

Finally, consider a configuration in which one or more lines of an NCP TG are connected to a router and one or more lines are directly connected between NCPs. If the network delay associated with one line of an NCP TG is different from the delay of another line in the same NCP TG, the receiving NCP spends additional time resequencing PIUs.

Setting Up STUN Traffic Priorities

To determine the order in which traffic should be handled on the network, use the methods described in the following sections:

•Assigning Queueing Priorities

•Prioritizing STUN Traffic over All Other Traffic

Assigning Queueing Priorities

To assign queueing priorities, perform the tasks in one of the following sections:

•Prioritizing by Serial Interface Address or TCP Port

•Prioritizing by Logical Unit Address

Prioritizing by Serial Interface Address or TCP Port

You can prioritize traffic on a per-serial-interface address or TCP port basis. You might want to do this so that traffic between one source-destination pair is always sent before traffic between another source-destination pair.

Note You must first enable local acknowledgment and priority levels as described earlier in this chapter.

To prioritize traffic, use one of the following commands in global configuration mode, as needed:

You must also use the following command in interface configuration mode:

Figure 9 illustrates serial link address prioritization. Device A communicates with Device C, and Device B communicates with Device D. With the serial link address prioritization, you can choose to give A-C a higher priority over B-D across the serial tunnel.

Figure 9 Serial Link Address Prioritization

To disable priorities, use the no forms of these commands.

For an example of how to prioritize traffic according to serial link address, see the "Example: Serial Link Address Prioritization Using STUN TCP/IP Encapsulation" section.

Prioritizing by Logical Unit Address

SNA local logical unit (LU) address prioritization is specific to IBM SNA connectivity and is used to prioritize SNA traffic on either STUN or remote source-route bridging (RSRB). To set the queueing priority by LU address, use the following command in global configuration mode:

In Figure 10, LU address prioritization can be set so that particular LUs receive data in preference to others or so that LUs have priority over the printer, for example.

Figure 10 SNA LU Address Prioritization

To disable this priority, use the no form of this command.

For an example of how to prioritize traffic according to logical unit address, see the "Example: LOCADDR Priority Groups for STUN" section.

Prioritizing STUN Traffic over All Other Traffic

You can prioritize STUN traffic to be routed first before all other traffic on the network. To give STUN traffic this priority, use the following command in global configuration mode:

To disable this priority, use the no form of this command.

For an example of how to prioritize STUN traffic over all other traffic, see the "Example: Serial Link Address Prioritization Using STUN TCP/IP Encapsulation" section.

Monitoring and Maintaining STUN Network Activity

You can list statistics regarding STUN interfaces, protocol groups, number of packets sent and received, local acknowledgment states, and more. To get activity information, use the following command in privileged EXEC mode:

Enabling BSTUN

To enable BSTUN in IP networks, use the following commands in global configuration mode:

The IP address in the bstun peer-name command defines the address by which this BSTUN peer is known to other BSTUN peers that are using the TCP transport. If this command is unconfigured or the no form of this command is specified, all BSTUN routing commands with IP addresses are deleted. BSTUN routing commands without IP addresses are not affected by this command.

The bstun lisnsap command specifies a SAP on which to detect incoming calls.

Defining the Protocol Group

Define a BSTUN group and specify the protocol it uses. To define the protocol group, use the following command in global configuration mode:

The bsc-local-ack protocol option only works for 3270 Bisync uses.

The block serial protocols include bsc, bsc-local-ack, adplex, adt-poll-select, adt-vari-poll, diebold, async-generic, and mdi.

Traditionally, the adt-poll-select protocol is used over land-based links, while the adt-vari-poll protocol is used over satellite (VSAT) links. The adt-vari-poll protocol typically uses a much slower polling rate when alarm consoles poll alarm panels because adt-vari-poll allows alarm panels to send unsolicited messages to the alarm console. In an adt-vari-poll configuration, alarm panels do not have wait for the console to poll them before responding with an alarm, they automatically send the alarm.

Interfaces configured to run the adplex protocol have their baud rate set to 4800 bps, use even parity, 8 data bits, 1 start bit, and 1 stop bit.

Interfaces configured to run the adt-poll-select and adt-vari-poll protocols have their baud rate set to 600 bps, use even parity, 8 data bits, 1 start bit, and 1.5 stop bits. If different line configurations are required, use the rxspeed, txspeed, databits, stopbits, and parity line configuration commands to change the line attributes.

Interfaces configured to run the diebold protocol have their baud rate set to 300 bps, use even parity, 8 data bits, 1 start bit, and 2 stop bits. If different line configurations are required, use the rxspeed, txspeed, databits, and parity line configuration commands to change the line attributes.

Interfaces configured to run the async-generic protocol have their baud rate set to 9600 bps, use no parity, 8 data bits, 1 start bit, and 1 stop bit. If different line configurations are required, use the rxspeed, txspeed, databits, stopbits, and parity line configuration commands to change the line attributes.

Interfaces configured to run the mdi protocol have their baud rate set to 600 bps, use even parity, 8 data bits, 1 start bit, and 1.5 stop bits. If different line configurations are required, use the rxspeed, txspeed, databits, stopbits, and parity line configuration commands to change the line attributes. The mdi protocol allows alarm panels to be sent to the MDI alarm console.

Enabling BSTUN Keepalive

To define the number of times to attempt a peer connection before declaring the peer connection be down, use the following command in global configuration mode:

Enabling BSTUN Remote Keepalive

To enable detection of the loss of a peer, use the following command in global configuration mode:

:

Enabling Frame Relay Encapsulation

To enable Frame Relay encapsulation, use the following commands beginning in global configuration mode:

Defining Mapping Between BSTUN and DLCI

To configure the mapping between BSTUN and the DLCI, use one of the following commands in interface configuration mode, as needed:

Note Direct encapsulation over Frame Relay is supported only for an encapsulation type of cisco, configured using the encapsulation frame-relay command.

Configuring BSTUN on the Serial Interface

Configure BSTUN on the serial interface before issuing any further BSTUN or protocol configuration commands for the interface. To configure the BSTUN function on a specified interface, use the following commands in interface configuration mode:

Note Configure the encapsulation bstun command on an interface before configuring any other BSTUN commands for the interface.

Placing a Serial Interface in a BSTUN Group

Each BSTUN-enabled interface on a router must be placed in a previously defined BSTUN group. Packets will only travel between BSTUN-enabled interfaces that are in the same group. To assign a serial interface to a BSTUN group, use the following command in interface configuration mode:

Specifying How Frames Are Forwarded

To specify how frames are forwarded when received on a BSTUN interface, use one of the following commands in interface configuration mode, as needed:

Note Every BSTUN route statement must have a corresponding route statement on the BSTUN peer. For example, a bstun route address address1 tcp peer2ip statement on PEER1 must have a corresponding bstun route address address1 tcp peer1ip statement on PEER2. Similarly, a bstun route address statement cannot map to a bstun route all statement, and vice versa.

For Bisync local acknowledgment, we recommend that you use the bstun route all tcp command. This command reduces the amount of duplicate configuration detail that would otherwise be needed to specify devices at each end of the tunnel.

Setting Up BSTUN Traffic Priorities

You can assign BSTUN traffic priorities based on either the BSTUN header or the TCP port. To prioritize traffic, use one of the following commands in global configuration mode, as needed:

You can customize BSTUN queueing priorities based on either the BSTUN header or TCP port. To customize priorities, use one of the following commands in global configuration mode, as needed:

Note Because the asynchronous security protocols share the same tunnels with Bisync when configured on the same routers, any traffic priorities configured for the tunnel apply to both Bisync and the various asynchronous security protocols.

Configuring Protocol Group Options on a Serial Interface

Depending on the selected block serial protocol group, you must configure one or more options for that protocol group. The options for each of these protocol groups are explained in the following sections:

•Configuring Bisync Options on a Serial Interface

•Configuring Asynchronous Security Protocol Options on a Serial Interface

Configuring Bisync Options on a Serial Interface

To configure Bisync options on a serial interface, use one of the following commands in interface configuration mode, as needed:

Configuring Asynchronous Security Protocol Options on a Serial Interface

To configure asynchronous security protocol options on a serial interface, use one or more of the following commands in interface configuration mode:

Configuring Direct Serial Encapsulation for Passthrough Peers

To configure direct serial encapsulation for passthrough peers, use the following command in interface configuration mode:

Configuring Local Acknowledgment Peers

To configure local acknowledgment peers, use the following command in interface configuration mode:

Monitoring and Maintaining the Status of BSTUN

To list statistics for BSTUN interfaces, protocol groups, number of packets sent and received, local acknowledgment states, and other activity information, use the following commands in EXEC mode:

Configuration Examples for Serial Tunnel and Block Serial Tunnel

The following sections provide STUN and BSTUN configuration examples:

•Example: STUN Priorities Using HDLC Encapsulation, page 15

•Example: SDLC Broadcast, page 16

•Example: Serial Link Address Prioritization Using STUN TCP/IP Encapsulation, page 17

•Example: STUN Local Acknowledgment for Frame Relay, page 21

•Example: LOCADDR Priority Groups, page 21

•Block Serial Tunneling (BSTUN) Overview

•Example: Simple Bisync Configuration

•Example: Bisync Addressing on Contention Interfaces

•Example: Nonstandard Bisync Addressing

•Example: Priority Queueing: With Priority Based on BSTUN Header

•Example: Priority Queueing: With Priority Based on BSTUN Header and Packet Sizes

•Example: Priority Queueing: With Priority Based on BSTUN Header and Bisync Address

•Priority Queueing: With Priority Based on BSTUN TCP Ports Example

•Example: Priority Queueing: With Priority Based on BSTUN TCP Ports and Bisync Address

•Example: Custom Queueing: With Priority Based on BSTUN Header

•Example: Custom Queueing: With Priority Based on BSTUN Header and Packet Size

•Example: Custom Queueing: With Priority Based on BSTUN Header and Bisync Address

•Example: Custom Queueing: With Priority Based on BSTUN TCP Ports

•Example: Custom Queueing: With Priority Based on BSTUN TCP Ports and Bisync Address

•Example: Asynchronous Configuration

•Example: BSTUN-over-Frame Relay Configuration with Local Acknowledgment

•Example: BSTUN-over-Frame Relay Configuration with Passthrough

Example: STUN Priorities Using HDLC Encapsulation

Assume that the link between Router A and Router B in Figure 11 is a serial tunnel that uses the simple serial transport mechanism. Device A communicates with Device C (SDLC address C1) with a high priority. Device B communicates with Device D (SDLC address A7) with a normal priority.

Figure 11 STUN Simple Serial Transport

The following configurations set the priority of STUN hosts A, B, C, and D.

Router A

stun peer-name 10.0.0.1

stun protocol-group 1 sdlc

stun protocol-group 2 sdlc

!

interface serial 0

 no ip address

 encapsulation stun

 stun group 1

 stun route address C1 interface serial 2

!

interface serial 1

 no ip address

 encapsulation stun 

 stun group 2

 stun route address A7 interface serial 2

!

interface serial 2

 ip address 10.0.0.1 255.0.0.0

 priority-group 1

!

priority-list 1 protocol stun high address 1 C1

priority-list 1 protocol stun low address 2 A7

Router B

stun peer-name 10.0.0.2

stun protocol-group 1 sdlc

stun protocol-group 2 sdlc

!

interface serial 0

 no ip address

 encapsulation stun

 stun group 1

 stun route address C1 interface serial 1

!

interface serial 1

 ip address 10.0.0.2 255.0.0.0

 priority-group 1

!

interface serial 2

 no ip address

 encapsulation stun

 stun group 2

 stun route address A7 interface serial 1

!

priority-list 1 protocol stun high address 1 C1

priority-list 1 protocol stun low address 2 A7

Example: SDLC Broadcast

In the following example, an FEP views end stations 1, 2, and 3 as if they were on an SDLC multidrop link. Any broadcast frame sent from the FEP to Router A is duplicated and sent to each of the downstream routers (B and C.)

stun peer-name xxx.xxx.xxx.xxx

stun protocol-group 1 sdlc

interface serial 1

encapsulation stun

 stun group 1

 stun sdlc-role secondary

 sdlc virtual-multidrop

 sdlc address 1

 sdlc address 2

 sdlc address 3

 stun route address 1 tcp yyy.yyy.yyy.yyy local-ack

 stun route address 2 tcp zzz.zzz.zzz.zzz local-ack

 stun route address 3 tcp zzz.zzz.zzz.zzz local-ack

 stun route address FF tcp yyy.yyy.yyy.yyy

 stun route address FF tcp zzz.zzz.zzz.zzz

Example: Serial Link Address Prioritization Using STUN TCP/IP Encapsulation

Assume that the link between Router A and Router B is a serial tunnel that uses the TCP/IP encapsulation as shown in Figure 12. Device A communicates with Device C (SDLC address C1) with a high priority. Device B communicates with Device D (SDLC address A7) with a normal priority. The configuration file for each router follows the figure.

Figure 12 STUN TCP/IP Encapsulation

Router A

stun peer-name 10.0.0.1

stun protocol-group 1 sdlc

stun protocol-group 2 sdlc

!

interface serial 0

 no ip address

 encapsulation stun

 stun group 1

 stun route address C1 tcp 10.0.0.2 local-ack priority

 priority-group 1

!

interface serial 1

 no ip address

 encapsulation stun

 stun group 2

 stun route address A7 tcp 10.0.0.2 local-ack priority

 priority-group 2

!

interface ethernet 0

 ip address 10.0.0.1 255.0.0.0

 priority-group 3

!

interface ethernet 1

 ip address 10.0.0.3 255.0.0.0

priority-group 3

! This list tells interface Serial 0 which tcp port numbers on the WAN interface

! correspond to the high, medium, normal and low priority queues.

priority-list 1 protocol ip high tcp 1994

priority-list 1 protocol ip medium tcp 1990

priority-list 1 protocol ip normal tcp 1991

priority-list 1 protocol ip low tcp 1992

priority-list 1 protocol stun high address 1 C1

! This list tells interface Serial 1 which tcp port numbers

! on the WAN interface correspond to the high, medium, normal

! and low priority queues.

priority-list 2 protocol ip high tcp 1994

priority-list 2 protocol ip medium tcp 1990

priority-list 2 protocol ip normal tcp 1991

priority-list 2 protocol ip low tcp 1992

priority-list 2 protocol stun normal address 2 A7

! This list establishes the high, medium, normal, and low

! priority queues on the WAN interfaces.

priority-list 3 protocol ip high tcp 1994

priority-list 3 protocol ip medium tcp 1990

priority-list 3 protocol ip normal tcp 1991

priority-list 3 protocol ip low tcp 1992

!

hostname routerA

router igrp

network 1.0.0.0

Router B

stun peer-name 10.0.0.2

stun protocol-group 1 sdlc

stun protocol-group 2 sdlc

!

interface serial 0

 no ip address

 encapsulation stun

 stun group 1

 stun route address C1 tcp 10.0.0.1 local-ack priority

 priority-group 1

!

interface serial 2

 no ip address

 encapsulation stun

 stun group 2

 stun route address A7 tcp 10.0.0.1 local-ack priority

 priority-group 2

!

interface ethernet 0

 ip address 10.0.0.2 255.0.0.0

priority-group 3

!

interface ethernet 1

 ip address 10.0.0.4 255.0.0.0

priority-group 3

! This list tells interface Serial 0 which tcp port numbers

! on the WAN interface correspond to the high, medium, normal

! and low priority queues.

priority-list 1 protocol ip high tcp 1994

priority-list 1 protocol ip medium tcp 1990

priority-list 1 protocol ip normal tcp 1991

priority-list 1 protocol ip low tcp 1992

priority-list 1 protocol stun high address 1 C1

! This list tells interface Serial 2 which tcp port numbers

! on the WAN interface correspond to the high, medium, normal

! and low priority queues.

priority-list 2 protocol ip high tcp 1994

priority-list 2 protocol ip medium tcp 1990

priority-list 2 protocol ip normal tcp 1991

priority-list 2 protocol ip low tcp 1992

priority-list 2 protocol stun normal address 2 A7

! This list establishes the high, medium, normal, and low

! priority queues on the WAN interface(s).

priority-list 3 protocol ip high tcp 1994

priority-list 3 protocol ip medium tcp 1990

priority-list 3 protocol ip normal tcp 1991

priority-list 3 protocol ip low tcp 1992

!

hostname routerB

router igrp 109

network 1.0.0.0

Example: STUN Multipoint Implementation Using a Line-Sharing Device

In Figure 13, four separate PS/2 computers are connected to a line-sharing device off of Router B. Each PS/2 computer has four sessions open on an AS/400 device attached to Router A. Router B functions as the primary station, while Router A functions as the secondary station. Both routers locally acknowledge packets from the IBM PS/2 systems.

Figure 13 STUN Communication Involving a Line-Sharing Device

The configuration file for the routers shown in Figure 13 follows.

Router A

! enter the address of the stun peer

stun peer-name 172.16.134.86

! specify that group 4 uses the SDLC protocol

stun protocol-group 4 sdlc

stun remote-peer-keepalive

!

interface ethernet 1

! enter the IP address for the Ethernet interface

 ip address 172.16.134.86 255.255.255.0

! description of IBM AS/400 link

interface serial 2

! description of IBM AS/400 link; disable the IP address on a serial interface 

 no ip address

! enable STUN encapsulation on this interface 

 encapsulation stun

! apply previously defined stun group 4 to serial interface 2

 stun group 4

! establish this router as a secondary station

stun sdlc-role secondary

! wait up to 63000 msec for a poll from the primary before timing out

 sdlc poll-wait-timeout 63000

! list addresses of secondary stations (PS/2 systems) attached to link

sdlc address C1

sdlc address C2

sdlc address C3

sdlc address C4

! use tcp encapsulation to send frames to SDLC stations C1, C2, C3, or 

! C4 and locally terminate sessions with these stations 

stun route address C1 tcp 172.16.134.58 local-ack

stun route address C2 tcp 172.16.134.58 local-ack

stun route address C3 tcp 172.16.134.58 local-ack

stun route address C4 tcp 172.16.134.58 local-ack

Router B

! enter the address of the stun peer 

stun peer-name 172.16.134.58

! this router is part of SDLC group 4

stun protocol-group 4 sdlc

stun remote-peer-keepalive

!

interface ethernet 1

! enter the IP address for the Ethernet interface

ip address 172.16.134.58 255.255.255.0

!

! description of PS/2 link 

interface serial 4

! disable the IP address on a serial interface 

 no ip address

! enable STUN encapsulation on this interface 

 encapsulation stun

! apply previously defined stun group 4 to serial interface 2

stun group 4

! establish this router as a primary station

stun sdlc-role primary

sdlc line-speed 9600

! wait 2000 milliseconds for a reply to a frame before resending it

sdlc t1 2000

! resend a frame up to four times if not acknowledged

sdlc n2 4

! list addresses of secondary stations (PS/2 systems) attached to link

sdlc address C1

sdlc address C2

sdlc address C3

sdlc address C4

! use tcp encapsulation to send frames to SDLC stations C1, C2, C3, or 

! C4 and locally terminate sessions with these stations 

stun route address C3 tcp 172.16.134.86 local-ack

stun route address C1 tcp 172.16.134.86 local-ack

stun route address C4 tcp 172.16.134.86 local-ack

stun route address C2 tcp 172.16.134.86 local-ack

! set the clock rate on this interface to 9600 bits per second 

clock rate 9600

Example: STUN Local Acknowledgment for SDLC

The following example shows a sample configuration for a pair of routers performing SDLC local acknowledgment.

Router A

stun peer-name 172.16.64.92

stun protocol-group 1 sdlc

stun remote-peer-keepalive

!

interface Serial 0

 no ip address

 encapsulation stun

 stun group 1

 stun sdlc-role secondary 

 sdlc address C1

 stun route address C1 tcp 172.16.64.93 local-ack

 clock rate 19200

Router B

stun peer-name 172.16.64.93

stun protocol-group 1 sdlc

stun remote-peer-keepalive

!

interface Serial 0

 no ip address

 encapsulation stun

 stun group 1

 stun sdlc-role primary 

 sdlc line-speed 19200

 sdlc address C1

 stun route address C1 tcp 172.16.64.92 local-ack

 clock rate 19200

Example: STUN Local Acknowledgment for Frame Relay

The following example describes an interface configuration for Frame Relay STUN with local acknowledgment:

stun peer-name 10.1.21.1 cls 4

stun protocol-group 120 sdlc

!

interface Serial1

 no ip address

 encapsulation frame-relay

 frame-relay lmi-type ansi

 frame-relay map llc2 22

!

interface Serial4

 no ip address

 encapsulation stun

 clock rate 9600

 stun group 120

 stun sdlc-role secondary

 sdlc address C1

 sdlc address C2

 stun route address C1 interface Serial1 dlci 22 04 local-ack

 stun route address C2 interface Serial1 dlci 22 08 local-ack

Example: LOCADDR Priority Groups

The following example shows how to establish queueing priorities on a STUN interface based on an LU address:

stun peer-name 131.108.254.6

stun protocol-group 1 sdlc 

! give locaddr-priority-list 1 a high priority for LU 02

locaddr-priority-list 1 02 high

! give locaddr-priority-list 1 a low priority for LU 05

locaddr-priority-list 1 05 low

!

interface serial 0

! disable the ip address for interface serial 0

 no ip address

! enable the interface for STUN

 encapsulation stun

 stun group 2 

 stun route address 10 tcp 131.108.254.8 local-ack priority

! assign priority group 1 to the input side of interface serial 0

locaddr-priority 1

priority-group 1

Example: LOCADDR Priority Groups for STUN

The following configuration example shows how to assign a priority group to an input interface:

Router A

stun peer-name 10.0.0.1

stun protocol-group 1 sdlc

locaddr-priority-list 1 02 high

locaddr-priority-list 1 03 high

locaddr-priority-list 1 04 medium

locaddr-priority-list 1 05 low

!

interface serial 0

 no ip address

 encapsulation stun

 stun group 1

 stun route address C1 tcp 10.0.0.2 local-ack priority

 clock rate 19200

 locaddr-priority 1

 priority-group 1

!

interface Ethernet 0

 ip address 10.0.0.1 255.255.255.0

!

 priority-list 1 protocol ip high tcp 1994

 priority-list 1 protocol ip medium tcp 1990

 priority-list 1 protocol ip normal tcp 1991

 priority-list 1 protocol ip low tcp 1992

Router B

stun peer-name 10.0.0.2

stun protocol-group 1 sdlc

locaddr-priority-list 1 02 high

locaddr-priority-list 1 03 high

locaddr-priority-list 1 04 medium

locaddr-priority-list 1 05 low

!

interface serial 0

 no ip address

 encapsulation stun

 stun group 1

 stun route address C1 tcp 10.0.0.1 local-ack priority

 clock rate 19200

 locaddr-priority 1

 priority-group 1

!

interface Ethernet 0

 ip address 10.0.0.2 255.255.255.0

!

 priority-list 1 protocol ip high tcp 1994

 priority-list 1 protocol ip medium tcp 1990

 priority-list 1 protocol ip normal tcp 1991

 priority-list 1 protocol ip low tcp 1992

BSTUN Configuration Examples

The following sections provide BSTUN configuration examples:

•Example: Simple Bisync Configuration

•Example: Bisync Addressing on Contention Interfaces

•Example: Nonstandard Bisync Addressing

•Example: Priority Queueing: With Priority Based on BSTUN Header

•Example: Priority Queueing: With Priority Based on BSTUN Header and Packet Sizes

•Example: Priority Queueing: With Priority Based on BSTUN Header and Bisync Address

•Priority Queueing: With Priority Based on BSTUN TCP Ports Example

•Example: Priority Queueing: With Priority Based on BSTUN TCP Ports and Bisync Address

•Example: Custom Queueing: With Priority Based on BSTUN Header

•Example: Custom Queueing: With Priority Based on BSTUN Header and Packet Size

•Example: Custom Queueing: With Priority Based on BSTUN Header and Bisync Address

•Example: Custom Queueing: With Priority Based on BSTUN TCP Ports

•Example: Custom Queueing: With Priority Based on BSTUN TCP Ports and Bisync Address

•Example: Asynchronous Configuration

•Example: BSTUN-over-Frame Relay Configuration with Local Acknowledgment

•Example: BSTUN-over-Frame Relay Configuration with Passthrough

Example: Simple Bisync Configuration

Figure 14 shows a simple Bisync configuration example.

Figure 14 Simple Bisync Configuration

The configuration files for the routers shown in Figure 14 follows.

Router 45ka

version 10.2

!

hostname 45ka

!

no ip domain-lookup

!

bstun peer-name 172.30.254.201

bstun protocol-group 1 bsc

!

interface ethernet 0

 ip address 198.92.0.201 255.255.255.0

 media-type 10BaseT

!

interface ethernet 1

 no ip address

 shutdown

 media-type 10BaseT

!

interface serial 0

 no ip address

 encapsulation bstun

 clock rate 19200

 bstun group 1

 bsc char-set ebcdic

 bsc secondary

 bstun route address C9 tcp 172.30.254.210

bstun route address C8 tcp 172.30.254.210

bstun route address C7 tcp 172.30.254.208

bstun route address C6 tcp 172.30.254.208

bstun route address C5 tcp 172.30.254.208

bstun route address C4 tcp 172.30.254.208

bstun route address C3 tcp 172.30.254.207

bstun route address C2 tcp 172.30.254.207

bstun route address C1 tcp 172.30.254.207

bstun route address 40 tcp 172.30.254.207

!

interface serial 1

no ip address

shutdown

!

interface serial 2

 no ip address

 shutdown

!

interface serial 3

 no ip address

 shutdown

!

interface tokenring 0

 no ip address

 shutdown

!

interface tokenring 1

 ip address 172.30.254.201 255.255.255.0

 ring-speed 16

!

line con 0

line aux 0

line vty 0 4

login

!

end

Router 25ka

version 10.2

!

hostname 25ka

!

no ip domain-lookup

!

bstun peer-name 172.30.254.207

bstun protocol-group 1 bsc

!

interface serial 0

 no ip address

 shutdown

!

interface serial 1

 no ip address

 encapsulation bstun

 clock rate 19200

 bstun group 1

 bsc char-set ebcdic

 bsc primary

 bstun route address C3 tcp 172.30.254.201

 bstun route address C2 tcp 172.30.254.201

 bstun route address C1 tcp 172.30.254.201

 bstun route address 40 tcp 172.30.254.201

!

interface tokenring 0

 ip address 172.30.254.207 255.255.255.0

 ring-speed 16

!

interface bri 0

 no ip address

 shutdown

!

line con 0

line aux 0

line vty 0 4

login

!

end

Configuration for Router 4kc

version 10.2

!

hostname 4kc

!

no ip domain-lookup

!

bstun peer-name 172.30.254.210

bstun protocol-group 1 bsc

!

interface ethernet 0

 ip address 198.92.0.210 255.255.255.0

 media-type 10BaseT

!

interface serial 0

 no ip address

 encapsulation bstun

 clock rate 19200

 bstun group 1

 bsc char-set ebcdic

 bsc primary

 bstun route address C9 tcp 172.30.254.201

 bstun route address C8 tcp 172.30.254.201

!

interface serial 1

 no ip address

 shutdown

!

interface serial 2

 no ip address

 shutdown

!

interface serial 3

 no ip address

 shutdown

!

interface tokenring 0

 ip address 172.30.254.210 255.255.255.0

 ring-speed 16

!

interface tokenring 1

 no ip address

 shutdown!

line con 0

line aux 0

line vty 0 4

login

!

end

Router 25kb

version 10.2

!

hostname 25kb

!

no ip domain-lookup

!

bstun peer-name 172.30.254.208

bstun protocol-group 1 bsc

!

interface serial 0

 no ip address

 encapsulation bstun

 no keepalive

 clock rate 19200

 bstun group 1

 bsc char-set ebcdic

 bsc primary

 bstun route address C7 tcp 172.30.254.201

 bstun route address C6 tcp 172.30.254.201

 bstun route address C5 tcp 172.30.254.201

 bstun route address C4 tcp 172.30.254.201

!

interface serial 1

 no ip address

 shutdown

!

interface tokenring 0

 ip address 172.30.254.208 255.255.255.0

 ring-speed 16

!

!

line con 0

line aux 0

line vty 0 4

login

!

end

Example: Bisync Addressing on Contention Interfaces

The following examples show user-configurable addressing on contention interfaces:

Remote Devices

bstun peer-name 1.1.1.20

bstun protocol-group 1 bsc

interface serial 0

 bstun group 1

 bsc contention 20

 bstun route address 20 tcp 1.1.1.1

Host Device

bstun peer-name 1.1.1.1

bstun protocol-group 1 bsc

interface serial 0

 bstun group 1

 bsc dial-contention 100

 bstun route address 20 tcp 1.1.1.20

 bstun route address 21 tcp 1.1.1.21

Example: Nonstandard Bisync Addressing

This example specifies an extended address on serial interface 0:

bstun peer-name 1.1.1.1

bstun protocol-group 1 bsc

!

interface serial 0

 bstun group 1

 bsc extended-address 23 83

 bsc extended-address 87 42

 bsc primary

 bstun route address 23 tcp 1.1.1.20

Example: Priority Queueing: With Priority Based on BSTUN Header

In the following example, the output interface examines header info and places packets with the BSTUN header on specified output queue:

priority-list 1 protocol bstun normal

interface serial 0

 priority-group 1

interface serial 1

 encapsulation bstun

 bstun group 1

 bsc char-set ebcdic

 bstun route all interface serial 0

                ...or...

bstun route address C1 interface serial 0

Example: Priority Queueing: With Priority Based on BSTUN Header and Packet Sizes

In the following example, the output interface examines header information and packet size and places packets with the BSTUN header that match criteria (gt or lt specified packet size) on specified output queue:

priority-list 1 protocol bstun low gt 1500

priority-list 1 protocol bstun hi lt 500

interface serial 0 

 priority-group 1

interface serial 1

 encapsulation bstun

 bstun group 1

 bsc char-set ebcdic

 bstun route all interface serial 0

                ...or...

bstun route address C1 interface serial 0

Example: Priority Queueing: With Priority Based on BSTUN Header and Bisync Address

In the following example, the output interface examines header information and Bisync address and places packets with the BSTUN header that match Bisync address on specified output queue:

priority-list 1 protocol bstun normal address 1 C1

interface serial 0

 priority-group 1

interface serial 1

 encapsulation bstun

 bstun group 1

 bsc char-set ebcdic

 bstun route address C1 interface serial 0

Priority Queueing: With Priority Based on BSTUN TCP Ports Example

In the following example, the output interface examines TCP port number and places packets with the BSTUN port number (1976) on specified output queue:

priority-list 1 protocol ip high tcp 1976

interface serial 0

 priority-group 1

interface serial 1

 encapsulation bstun

 bstun group 1

 bstun route all tcp 200.190.30.1

Example: Priority Queueing: With Priority Based on BSTUN TCP Ports and Bisync Address

In the following example, four TCP/IP sessions (high, medium, normal, and low) are established with BSTUN peers using BSTUN port numbers. The input interface examines the Bisync address and uses the specified output queue definition to determine which BSTUN TCP session to use for sending the packet to the BSTUN peer.

The output interface examines the TCP port number and places packets with the BSTUN port numbers on the specified output queue.

priority-list 1 protocol ip high   tcp 1976

priority-list 1 protocol ip medium tcp 1977

priority-list 1 protocol ip normal tcp 1978

priority-list 1 protocol ip low    tcp 1979

!

priority-list 1 protocol bstun normal address 1 C1

!

interface serial 0

 priority-group 1

! 

interface serial 1

 encapsulation bstun

 bstun group 1

 bsc char-set ebcdic

 bstun route address C1 tcp 200.190.30.1 priority

 priority-group 1

Example: Custom Queueing: With Priority Based on BSTUN Header

In the following example, the output interface examines header info and places packets with the BSTUN header on specified output queue.

queue-list 1 protocol bstun normal

! 

interface serial 0

 custom-queue-list 1

! 

interface serial 1

 encapsulation bstun

 bstun group 1

 bstun route all interface serial 0

Example: Custom Queueing: With Priority Based on BSTUN Header and Packet Size

In the following example, the output interface examines header information and packet size and places packets with the BSTUN header that match criteria (gt or lt specified packet size) on specified output queue.

queue-list 1 protocol bstun low gt 1500

queue-list 1 protocol bstun high lt 500

! 

interface serial 0

 custom-queue-list 1

! 

interface serial 1

 encapsulation bstun

 bstun group 1

 bstun route all interface serial 0

Example: Custom Queueing: With Priority Based on BSTUN Header and Bisync Address

In the following example, the output interface examines header info and Bisync address and places packets with the BSTUN header that match Bisync address on specified output queue.

queue-list 1 protocol bstun normal address 1 C1

! 

interface serial 0

 custom-queue-list 1

!

interface serial 1

 encapsulation bstun

 bstun group 1

 bsc char-set ebcdic

 bstun route address C1 interface serial 0

Example: Custom Queueing: With Priority Based on BSTUN TCP Ports

In the following example, the output interface examines the TCP port number and places packets with the BSTUN port number (1976) on specified output queue:

queue-list 1 protocol ip high tcp 1976

! 

interface serial 0

 custom-queue-list 1

!

interface serial 1

 encapsulation bstun

 bstun group 1

 bstun route all tcp 200.190.30.1

Example: Custom Queueing: With Priority Based on BSTUN TCP Ports and Bisync Address

In the following example, four TCP/IP sessions (high, medium, normal, and low) are established with BSTUN peers using BSTUN port numbers. The input interface examines the Bisync address and uses the specified output queue definition to determine which BSTUN TCP session to use.

The output interface examines the TCP port number and places packets with the BSTUN port numbers on the specified output queue.

For Bisync addressing, output queues map as shown in Table 1:

queue-list 1 protocol ip high tcp 1976

queue-list 1 protocol ip medium tcp 1977

queue-list 1 protocol ip normal tcp 1978

queue-list 1 protocol ip low tcp 1979

! 

priority-list 1 protocol bstun normal address 1 C1

! 

interface serial 0

 custom-queue-list 1

!

interface serial 1

 encapsulation bstun

 bstun group 1

 bsc char-set ebcdic

 bstun route address C1 tcp 200.190.30.1 priority

 custom-queue-list 1

Example: Asynchronous Configuration

In the following example, Router A and Router B are configured for both Adplex and Bisync across the same BSTUN as shown in Figure 15.

Figure 15 Combined Adplex and Bisync Configuration Example

Router A

version 11.0

!

hostname router-a

!

bstun peer-name 172.28.1.190

bstun protocol-group 1 bsc

bstun protocol-group 2 adplex

bstun protocol-group 3 adplex

!

interface serial 0

 no ip address

!

interface serial 1

 no ip address

!

interface serial 2

 physical-layer async

 description Connection to 1st Security Alarm Console.

 no ip address

 encapsulation bstun

 no keepalive

 bstun group 2

 bstun route address 2 tcp 172.28.1.189

 bstun route address 3 tcp 172.28.1.189

 adplex secondary

!

interface serial 3

 description Connection to BSC 3780 host.

 no ip address

 encapsulation bstun

 no keepalive

 clock rate 9600

 bstun group 1

 bstun route all tcp 172.28.1.189

 bsc char-set ebcdic

 bsc contention

!

interface serial 4

 physical-layer async

 description Connection to 2nd Security Alarm Console.

 no ip address

 encapsulation bstun

 no keepalive

 bstun group 3

 bstun route address 2 tcp 172.28.1.189

 bstun route address 3 tcp 172.28.1.189

 adplex secondary

!

interface serial 5

 no ip address

!

interface serial 6

 no ip address

!

interface serial 7

 no ip address

!

interface serial 8

 no ip address

!

interface serial 9

 no ip address

!

interface tokenring 0

 ip address 172.28.1.190 255.255.255.192

 ring-speed 16

!

interface BRI0

 ip address

 shutdown

!

ip host ss10 172.28.0.40

ip host s2000 172.31.0.2

ip route 0.0.0.0 0.0.0.0 172.28.1.129

!

snmp-server community public RO

!

line con 0

 exec-timeout 0 0

line 2

 no activation-character

 transport input-all

 parity even

 stopbits 1

 rxspeed 4800

 txspeed 4800

line 4

 transport input all

 parity even

 stopbits 1

 rxspeed 4800

 txspeed 4800

line aux 0

 transport input all

line vty 0 4

 password mango

 login

!

end

Router B

version 11.0

!

hostname router-b

!

bstun peer-name 172.28.1.189

bstun protocol-group 1 bsc

bstun protocol-group 2 adplex

bstun protocol-group 3 adplex

source-bridge ring-group 100

!

interface serial 0

 no ip address

!

interface serial 1

 no ip address

!

interface serial 2

 physical-layer async

 description Connection to Security Alarm Panel.

 no ip address

 encapsulation bstun

 no keepalive

 bstun group 2

 bstun route all tcp 172.28.1.190

 adplex primary

!

interface serial 3

 description Connection to BSC 3780 device.

 no ip address

 encapsulation bstun

 no keepalive

 clock rate 9600

 bstun group 1

 bstun route all tcp 172.28.1.190

 bsc char-set ebcdic

 bsc contention

!

interface serial 4

 physical-layer async

 description Connection to async port on NCD (VT100 terminal emulation).

 no ip address

!

interface serial 5

 no ip address

 encapsulation sdlc-primary

 no keepalive

 nrzi-encoding

 clock rate 9600

 sdllc traddr 4000.0000.4100 222 2 100

 sdlc address C1

 sdllc xid C1 05D40003

 sdllc partner 4000.0000.0307 C1

!

interface serial 6

 description Connection to alarm panel.

 physical-layer async

 no ip address

 encapsulation bstun

 no keepalive

 bstun group 3

 bstun route all tcp 172.28.1.190

 adplex primary

!interface serial 7

 no ip address

!

interface serial 8

 no ip address

!

interface serial 9

 no ip address

!

interface tokenring 0

 ip address 172.28.1.189 255.255.255.192

 ring-speed 16

 source-bridge 4 1 100

!

interface BRI0

 ip address

 shutdown

!

ip host ss10 172.28.0.40

ip host s2000 172.31.0.2

ip route 0.0.0.0 0.0.0.0 172.28.1.129

!

snmp-server community public RO

!

line con 0

 exec-timeout 0 0

line 2

 no activation-character

 transport input-all

 parity even

 stopbits 1

 rxspeed 4800

 txspeed 4800

line 4

 transport input all

 stopbits 1

line 6

 transport input all

 parity even

 stopbits 1

 rxspeed 4800

 txspeed 4800

line 7

 transport input all

line aux 0

 transport input all

line vty 0 4

 password mango

 login

!

end

Example: BSTUN-over-Frame Relay Configuration with Local Acknowledgment

The following example configures BSTUN over Frame Relay with local acknowledgment configured:

bstun protocol-group 1 bsc-local-ack

interface Serial1

 encapsulation frame-relay ietf

 clock rate 125000

 frame-relay map llc2 16

interface Serial4

 no ip address

encapsulation bstun

bstun group 1

bsc secondary 

bstun route address C3 interface Serial1 dlci 16 C

bstun route address C2 interface Serial1 dlci 16 8

bstun route address C1 interface Serial1 dlci 16 4

Example: BSTUN-over-Frame Relay Configuration with Passthrough

The following example configures BSTUN over Frame Relay with Passthrough configured:

bstun protocol-group 1 bsc

interface Serial1

 encapsulation frame-relay

 clock rate 125000

 frame-relay map bstun 16

 frame-relay map llc 16

interface Serial4

 no ip address

encapsulation bstun

bstun group 1

bsc secondary 

bstun route address C3 interface Serial1 dlci 16

bstun route address C2 interface Serial1 dlci 16

bstun route address C1 interface Serial1 dlci 16

Additional References

Related Documents

Standards

MIBs

RFCs

Technical Assistance

Feature Information for Configuring Serial Tunnel and Block Serial Tunnel

Table 2 lists the features in this module and provides links to specific configuration information.

Use Cisco Feature Navigator to find information about platform support and software image support. Cisco Feature Navigator enables you to determine which software images support a specific software release, feature set, or platform. To access Cisco Feature Navigator, go to http://www.cisco.com/go/cfn. An account on Cisco.com is not required.

Note Table 2 lists only the software release that introduced support for a given feature in a given software release train. Unless noted otherwise, subsequent releases of that software release train also support that feature.

Cisco and the Cisco Logo are trademarks of Cisco Systems, Inc. and/or its affiliates in the U.S. and other countries. A listing of Cisco's trademarks can be found at www.cisco.com/go/trademarks. Third party trademarks mentioned are the property of their respective owners. The use of the word partner does not imply a partnership relationship between Cisco and any other company. (1005R)

Any Internet Protocol (IP) addresses used in this document are not intended to be actual addresses. Any examples, command display output, and figures included in the document are shown for illustrative purposes only. Any use of actual IP addresses in illustrative content is unintentional and coincidental.

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