- Wide-Area Networking Overview
- Configuring SMDS
- Configuring X.25 and LAPB
- Terminal Line Security for PAD Connections
- X.25 Annex G Session Status Change Reporting
- X.25 Dual Serial Line Management
- X.25 over TCP Profiles
- X.25 Record Boundary Preservation for Data Communications Networks
- X.25 Suppression of Security Signaling Facilities
- X.25 Call Confirm Packet Address Control
- X.25 Data Display Trace
- X.25 Version Configuration
- X.25 Station Type for ISDN D-channel Interface
- X.25 Throughput Negotiation
- X.25 Facility Handling
- X.28 Configurable PAD Options
Contents
- X.25 Throughput Negotiation
- Finding Feature Information
- Restrictions for X.25 Throughput Negotiation
- Information about X.25 Throughput Negotiation
- How to Configure X.25 Throughput Negotiation
- Configuring X.25 Throughput Negotiation
- Configuration Examples for X.25 Throughput Negotiation
- Basic example
- Never example
- Additional References
X.25 Throughput Negotiation
This feature enables a router to negotiate X.25 throughput parameters on behalf of end devices, thereby making it possible for X.25 calls to reach devices that may not themselves be able to negotiate throughput.
History for the X.25 Throughput Negotiation Feature
|
Release |
Modification |
|---|---|
|
12.3(11)YN |
This feature was introduced. |
|
12.4(4)T |
This feature was integrated into Cisco IOS 12.4(4)T. |
Finding Support Information for Platforms and Cisco IOS Software Images
Use Cisco Feature Navigator to find information about platform support and Cisco IOS software image support. Access Cisco Feature Navigator at http://www.cisco.com/go/fn . You must have an account on Cisco.com. If you do not have an account or have forgotten your username or password, click Cancel when presented with the login screen and then follow the instructions that subsequently appear.
- Finding Feature Information
- Restrictions for X.25 Throughput Negotiation
- Information about X.25 Throughput Negotiation
- How to Configure X.25 Throughput Negotiation
- Configuration Examples for X.25 Throughput Negotiation
- Additional References
Finding Feature Information
Your software release may not support all the features documented in this module. For the latest caveats and feature information, see Bug Search Tool and 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 table at the end of this module.
Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to www.cisco.com/go/cfn. An account on Cisco.com is not required.
Restrictions for X.25 Throughput Negotiation
This feature currently supports only basic throughput classes; extended throughput classes are not supported.
Information about X.25 Throughput Negotiation
In order for end devices in a network to support X.25 calls, they need to be able to negotiate X.25 throughput parameters. This feature enables a router to handle that negotiation on behalf of end devices that cannot do it themselves.
The router does this by stripping out or inserting values, as appropriate for each case, in the "throughput facility field" of the X.25 calls’ setup and confirmed messages (specifically, in the Call Request, Incoming Call, Call Accepted, and Call Confirmed packets).
In order to insert values appropriately, the router interface connected to the end device must earlier have been configured with the input and output bit rates that are intended to be used by the eventual X.25 call.
The rules according to which the router removes or inserts those bit rates are set by the x25 subscribe throughput command, which can have three distinct states: no, basic or never. These forms of the command work as follows when the router receives a call from the network and forwards that call onward to the end device:
- If the router has been configured by the command no x25 subscribe throughput, it will make no change to the values it receives in the call’s facility field. The router merely forwards the message, and those values, onward.
- If the router has been configured by the 25 subscribe throughput basic form of this command, the router will insert the bit rate values previously configured on its interface into the call’s facility field. (The only exception is when those values are larger than the call’s values, in which case the router will leave the call’s smaller values in place when it forwards the message.)
In cases when the router has substituted its own configured values for the values it detected in the incoming call, the router also reports those new values in a Call Confirmed packet back out through the network to the source device.
- If the x25 subscribe throughput never form of the command has been entered, the router will remove the values it receives in the call’s facility field. (And if the values previously configured on the router’s interface are smaller than those contained in the call, the router will also replace the call’s values with those smaller ones when it forwards the end device’s Call Confirmed packet back out to the network.)
How these behavior rules apply to each possible case is presented in the first table below.
When calls originate not in the network but in the end device, this command’s three states can have somewhat different results, which are detailed in the second table below.
|
Incoming call’s ‘Call Request’ packet |
Cisco IOS commands applied |
Results |
||
|---|---|---|---|---|
|
Is interface configured with throughput values? |
How is Serial Line’s throughput subscription configured? |
Within ‘Incoming Call’ packet |
Within ‘Call Confirmed’ packet |
|
|
Contains throughput facility field |
YES : "x25 facility throughput xxx yyy |
no x25 sub throughput |
Facility field in message from network is sent to end device unmodified. |
End device includes no facility field in its Call Accepted packet to the router. And the router includes no facility field in the Call Confirmed packet it sends out to the network. |
|
x25 sub throughput never |
Router strips out facility field, then forwards message to end device. |
Router sends values out to network only if the values configured on its interface are smaller than those received in network call. |
||
|
x25 sub throughput basic |
Router compares values in message with those configured on its interface, and sends to end device the lower set. |
Router sends that lower set out to the network. |
||
|
Has no throughput facility field |
no x25 sub throughput |
No facility field sent to end device. |
No facility field sent out to network. |
|
|
x25 sub throughput never |
No facility field sent to end device. |
No facility field sent back out to network. |
||
|
x25 sub throughput basic |
Router inserts facility field into message, and forwards that to the end device. |
No facility field sent back out to network. |
||
|
Contains throughput facility field |
NO : "no x25 facility throughput" |
no x25 sub throughput |
Facility field sent to end device. |
End device includes no facility field in its Call Accepted packet to the router. And the router includes no facility field in the Call Confirmed packet it sends out to the network. |
|
x25 sub throughput never |
Router strips out facility field, then forwards message to end device. |
No facility field sent back out to network. |
||
|
x25 sub throughput basic |
Facility field sent on to end device. |
No facility field sent back out to network. |
||
|
Has no throughput facility field |
no x25 sub throughput |
No facility field sent to end device. |
No facility field sent out to network. |
|
|
x25 sub throughput never |
No facility field sent to end device. |
No facility field sent back out to network. |
||
|
x25 sub throughput basic |
No facility field sent to end device. |
No facility field sent out to network. |
*Shaded rows (in PDF version) describe calls that contain no throughput facility field before they reach the router.
|
Outgoing call’s ‘Call Request’ packet |
Cisco IOS commands applied |
Results |
||
|---|---|---|---|---|
|
Is interface configured with throughput values? |
How is Serial Line’s throughput subscription configured? |
Within outgoing ‘Call Request’ packet |
Within received ‘Call Confirmed’ packet |
|
|
Contains throughput facility field |
YES : "x25 facility throughput xxx yyy |
no x25 sub throughput |
Router forwards facility field it receives in the end device’s Call Request packet out to the network unmodified. |
Router forwards facility field it receives in the Call Confirmed packet from the network on to the end device unmodified. |
|
x25 sub throughput never |
Router refuses to forward call on to the network, and cancels it, sending back to the end device a Clear Request packet with the Cause Code field set to 3 (‘3’ stands for "Invalid Facility Request"). Router also sends to the end device a Diagnostic Code field set to 65 (which stands for "Facility Code Not Allowed"). |
|||
|
x25 sub throughput basic |
Router compares values in message with those configured on its interface, and sends to network the lower set. |
Router sends that lower set to the end device, unless still different values are received in the Call Confirmed message from the network. In that case, the router forwards that network set to the end device. |
||
|
Has no throughput facility field |
no x25 sub throughput |
No facility field sent to network. |
No facility field sent to end device. |
|
|
x25 sub throughput never |
Router sends values configured on its interface out to the network. |
No facility field sent to end device. |
||
|
x25 sub throughput basic |
Router inserts facility field into message, and forwards that to the network. |
Router sends the inserted facility field to the end device. |
||
|
Contains throughput facility field |
NO : "no x25 facility throughput" |
no x25 sub throughput |
Router forwards facility field it receives in the end device’s Call Request packet out to the network unmodified. |
Router forwards facility field it receives in the Call Confirmed packet from the network on to the end device unmodified. |
|
x25 sub throughput never |
Router refuses to forward call on to the network, and cancels it, sending back to the end device a Clear Request packet with the Cause Code field set to 3 (‘3’ stands for "Invalid Facility Request"). Router also sends to the end device a Diagnostic Code field set to 65 (which stands for "Facility Code Not Allowed"). |
|||
|
x25 sub throughput basic |
Facility field sent on to network. |
Facility field sent back to end device. |
||
|
Has no throughput facility field |
no x25 sub throughput |
No facility field sent to network. |
No facility field sent to end device. |
|
|
x25 sub throughput never |
No facility field sent to network. |
No facility field sent to end device. |
||
|
x25 sub throughput basic |
No facility field sent to network. |
No facility field sent to end device. |
*Shaded rows (in PDF version) describe calls that contain no throughput facility field before they reach the router.
How to Configure X.25 Throughput Negotiation
Configuring X.25 Throughput Negotiation
If you choose the basic keyword of the x25 subscribe throughput command below, you must first configure the interface with the appropriate class negotiation values for input and output throughput across the network by using the throughput in out keyword and arguments of the x25 facility command. For more information about the x25 facilitycommand, see the Cisco IOS Wide-Area Networking Command Reference.
1.
enable
2.
configure
terminal
3.
interface
interface-id
4.
x25
subscribe
throughput
{
never
|
basic
}
5.
exit
DETAILED STEPS
Examples
In this example, the end device never expects the throughput facility field to be present in incoming call setup packets:
Router> enable Router# configure terminal Router(config)# interface serial2/0 Router(config-if)# x25 subscribe throughput never Router(config-if)# exit
In this example, the end device always expects the throughput facility field to be present in incoming call setup packets:
Router> enable Router# configure terminal Router(config)# interface serial0/0 Router(config-if)# x25 subscribe throughput basic Router(config-if)# exit
In this example, the active throughput negotiation capability on the just-illustrated interface (Serial 0/0) gets turned off:
Router(config)# interface serial0/0 Router(config-if)# no x25 subscribe throughput Router(config-if)# exit
Configuration Examples for X.25 Throughput Negotiation
Basic example
In this example, the end device always expects the throughput facility field to be present in Incoming Call packets. The router inserts its configured bit rate values--unless they are larger than the values in the incoming call.
Router# configure terminal Router(config)# interface serial2/0 Router(config-if)# x25 facility throughput 300 300 Router(config-if)# x25 subscribe throughput basic Router(config-if)# end Router#
Never example
In this example, the end device never expects the throughput facility field to be present in Incoming Call packets. The router removes the facility field from incoming calls.
Router# configure terminal Router(config)# interface serial2/0 Router(config-if)# x25 facility throughput 300 300 Router(config-if)# x25 subscribe throughput never Router(config-if)# end Router#
Additional References
Related Documents
|
Related Topic |
Document Title |
|---|---|
|
Configuring X.25 throughput facilities |
Cisco IOS Wide-Area Networking Command Reference |
Technical Assistance
|
Description |
Link |
|---|---|
|
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