Configuring Pseudowire
Cisco Pseudowire Emulation Edge-to-Edge (PWE3) allows you to transport traffic by using traditional services such as T1/E1 over a packet-based backhaul technology such as MPLS or IP. A pseudowire (PW) consists of a connection between two provider edge (PE) chassis that connects two attachment circuits (ACs), such as T1/E1 or T3 /E3 links.
Information About Pseudowire
The following sections describe how to configure pseudowire on the interface module of the chassis.
Overview of Pseudowire
Pseudowires manage encapsulation, timing, order, and other operations in order to make it transparent to users. The pseudowire tunnel acts as an unshared link or circuit of the emulated service.
How to Configure Pseudowire
The following sections describe how to configure pseudowire.
Structure-Agnostic TDM over Packet
Structure-Agnostic TDM over Packet (SAToP) encapsulates Time Division Multiplexing (TDM) bit-streams as pseudowires over public switched networks. It disregards any structure that may be imposed on streams, in particular the structure imposed by the standard TDM framing.
The protocol used for emulation of these services does not depend on the method in which attachment circuits are delivered to the Provider Edge (PE) chassis. For example, a T1 attachment circuit is treated the same way for all delivery methods, including copper, multiplex in a T3 circuit, a virtual tributary of a SONET circuit, or unstructured Circuit Emulation Service (CES).
In SAToP mode, the interface is considered as a continuous framed bit stream. The packetization of the stream is done according to IETF RFC 4553. All signaling is carried out transparently as a part of a bit stream.
Configuring CEM for SAToP
This section provides information about how to configure CEM. CEM provides a bridge between a Time Division Multiplexing (TDM) network and a packet network, MPLS. The chassis encapsulates the TDM data in the MPLS packets and sends the data over a CEM pseudowire to the remote Provider Edge (PE) chassis.
The following sections describe how to configure CEM.
Configuring CEM Restriction
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Not all combinations of payload size and dejitter buffer size are supported. If you apply an incompatible payload size or dejitter buffer size configuration, the chassis rejects it and reverts to the previous configuration.
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The dummy-pattern command is not supported.
 Note |
CEM interface does not support idle-cas parameter. |
Configuring CEM Group for SAToP for T1 Interfaces
enable
configure terminal
controller t1 0/4/0
cem-group 0 unframed
end
Note |
You need metroaggrservice license to configure CEM group on the Interface Module. |
Configuring CEM Classes
A CEM class allows you to create a single configuration template for multiple CEM pseudowires. Follow these steps to configure a CEM class:
Note |
|
enable
configure terminal
class cem mycemclass
payload-size 512
dejitter-buffer 12
exit
interface cem 0/0/1
cem 0
cem class mycemclass
xconnect 10.10.10.10 200 encapsulation mpls
exit
Configuring CEM Parameters
The following sections describe the parameters you can configure for CEM circuits.
Configuring Payload Size
To specify the number of bytes encapsulated into a single IP packet, use the payload-size command. The size argument specifies the number of bytes in the payload of each packet. The range is from 32 to 1312 bytes.
Default payload sizes for an unstructured CEM channel are as follows:
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T1 = 192 bytes
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E1 = 256 bytes
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DS0 = 32 bytes
Default payload sizes for a structured CEM channel depend on the number of time slots that constitute the channel. Payload size (L in bytes), number of time slots (N), and packetization delay (D in milliseconds) have the following relationship: L = 8*N*D. The default payload size is selected in such a way that the packetization delay is always 1 millisecond. For example, a structured CEM channel of 16xDS0 has a default payload size of 128 bytes.
Note |
Both payload-size and dejitter-buffer must be configured simultaneously. |
Setting the Dejitter Buffer Size
To specify the size of the dejitter-buffer used to compensate for the network filter, use the dejitter-buffer command. The configured dejitter-buffer size is converted from milliseconds to packets and rounded up to the next integral number of packets. Use the size argument to specify the size of the buffer, in milliseconds. The range is from 1 to 32; the default is 5.
Shutting Down a CEM Channel
To shut down a CEM channel, use the shutdown command in CEM configuration mode. The shutdown command is supported only under CEM mode and not under the CEM class.
Configuring CEM Parameter on CEM Interface
The CEM parameters can be configured directly on CEM interface. Follow these steps to configure CEM parameters:
enable
configure terminal
interface cem 0/0/1
cem 0
payload-size 512 dejitter-buffer 12
xconnect 10.10.10.10 200 encapsulation mpls
exit
Verifying CEM Statistics for SAToP
Use the following commands to verify the pseudowire configuration for SAToP:
- show cem circuit —Displays information about the circuit state, administrative state, the CEM ID of the circuit, and the interface on which it is configured. If cross connect is configured under the circuit, the command output also includes information about the attachment circuit status.
Router# show cem circuit
<0-32000> CEM ID
detail Detailed information of cem ckt(s)
interface CEM Interface
summary Display summary of CEM ckts
| Output modifiers
Router# show cem circuit
CEM Int. ID Line Admin Circuit AC
--------------------------------------------------------------
CEM0/1/0 1 UP UP ACTIVE --/--
CEM0/1/0 2 UP UP ACTIVE --/--
CEM0/1/0 3 UP UP ACTIVE --/--
CEM0/1/0 4 UP UP ACTIVE --/--
CEM0/1/0 5 UP UP ACTIVE --/--
- show cem circuit cem-id — Displays the detailed information about that particular circuit.
Router# show cem circuit 0
CEM0/1/2, ID: 0, Line: UP, Admin: UP, Ckt: ACTIVE
Controller state: up, T1 state: up
Idle Pattern: 0xFF, Idle CAS: 0x8
Dejitter: 5 (In use: 0)
Payload Size: 192
Framing: Unframed
CEM Defects Set
None
Signalling: No CAS
RTP: No RTP
Ingress Pkts: 11060 Dropped: 0
Egress Pkts: 11061 Dropped: 0
CEM Counter Details
Input Errors: 0 Output Errors: 0
Pkts Missing: 0 Pkts Reordered: 0
Misorder Drops: 0 JitterBuf Underrun: 0
Error Sec: 0 Severly Errored Sec: 0
Unavailable Sec: 0 Failure Counts: 0
Pkts Malformed: 0 JitterBuf Overrun: 0
- show cem circuit summary — Displays the number of circuits which are up or down per interface basis.
Router# show cem circuit summary
CEM Int. Total Active Inactive
--------------------------------------
CEM0/1/0 1 1 0
Configuring Framed SAToP
Note |
Framing type should be maintained same in all routers end to end. |
enable
configure terminal
controller t1 0/0/0
framing esf
cem-group 0 framed
exit
Verifying CEM Statistics for Framed SAToP
Use the following commands to verify the pseudowire configuration for SAToP:
- show cem circuit —Displays information about the circuit state, administrative state, the CEM ID of the circuit, and the interface on which it is configured. If cross connect is configured under the circuit, the command output also includes information about the attachment circuit status.
Router# show cem circuit
<0-4294967295> CEM ID
detail Detailed information of cem ckt(s)
interface CEM Interface
summary Display summary of CEM ckts
| Output modifiers
Router# show cem circuit
CEM Int. ID Ctrlr Admin Circuit AC
--------------------------------------------------------------
CEM0/1/0 1 UP UP Active UP
CEM0/1/1 2 UP UP Active UP
CEM0/1/2 3 UP UP Active UP
CEM0/1/3 4 UP UP Active UP
CEM0/1/4 5 UP UP Active UP- show cem circuit cem-id — Displays the detailed information about that particular circuit.
Router# show cem circuit 0
CEM0/1/2, ID: 0, Line: UP, Admin: UP, Ckt: ACTIVE
Mode :T1, CEM Mode: T1-SAToP
Controller state: up, T1 state: up
Idle Pattern: 0xFF, Idle CAS: 0x8
Dejitter: 5 (In use: 0)
Payload Size: 192
Framing: Framed SAToP
CEM Defects Set
None
Signalling: No CAS
RTP: No RTP
Ingress Pkts: 167027103 Dropped: 0
Egress Pkts: 167027102 Dropped: 0
CEM Counter Details
Input Errors: 0 Output Errors: 0
Pkts Missing: 0 Pkts Reordered: 0
Misorder Drops: 0 JitterBuf Underrun: 0
Error Sec: 0 Severly Errored Sec: 0
Unavailable Sec: 0 Failure Counts: 0
Pkts Malformed: 0 JitterBuf Overrun: 0
Generated Lbits: 0 Received Lbits: 0
Generated Rbits: 0 Received Rbits: 0
- show cem circuit summary — Displays the number of circuits which are up or down per interface basis.
Router# show cem circuit summary
CEM Int. Total Active Inactive
--------------------------------------
CEM0/1/0 1 1 0
CEM0/1/1 1 1 0
CEM0/1/2 1 1 0
CEM0/1/3 1 1 0
CEM0/1/4 1 1 0
Circuit Emulation Service over Packet-Switched Network
CESoPSN is a method for encapsulating structured (NxDS0) TDM signals as pseudowires over packet switching networks.
Restrictions for CESoPSN on T1 Interface
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The maximum number of CEM interface supported is 192.
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DS0 loopback is not supported on the T1 interface.
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Alarm forwarding is not supported on the T1 interface.
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Card protection is not supported on the T1 interface.
Configuring CEM Group for CESoPSN on T1 Interface
The following section describes how to configure a CEM group for CESoPSN.
enable
configure terminal
controller t1 0/4/32
cem-group 0 timeslots 1-10
enable
configure terminal
interface cem 0/4/32
cem 0
xconnect 2.2.2.2 10 encapsulation mpls
Perform a similar configuration on the other end of the pseudowire.
show running-config | sec 0/8/16
controller T1 0/8/16
framing esf
linecode b8zs
cablelength short 110
cem-group 0 timeslots 1-10
interface CEM0/8/16
no ip address
cem 0
xconnect 2.2.2.2 10 encapsulation mpls
Check for cross-connect configuration using the following command:
Router#show xconnect all | i 0/4/32
UP pri ac CE0/4/32:0(CESoPSN Basic) UP mpls 2.2.2.2:10 UP
Router#sh controllers t1 0/4/32
T1 0/4/32 is up
Applique type is NCS4200-48T1E1-CE
Cablelength is short 110
No alarms detected.
alarm-trigger is not set
Soaking time: 3, Clearance time: 10
AIS State:Clear LOS State:Clear LOF State:Clear
Framing is ESF, Line Code is B8ZS, Clock Source is Line.
Verifying CEM for CESoPSN on T1 Interface
Use the following commands to verify the pseudowire configuration for CESoPSN:
-
show cem circuit—Displays information about the circuit state, administrative state, the CEM ID of the circuit, and the interface on which it is configured. If cross connect is configured under the circuit, the command output also includes information about the attachment circuit status.
-
show mpls l2 vc—Displays information about the MPLS VC.
-
show mpls l2 vc detail—Displays detailed information about the MPLS VC.
PE1#show mpls l2 vc 10
Local intf Local circuit Dest address VC ID Status
------------- -------------------------- --------------- ---------- ----------
CE0/4/32 CESoPSN Basic 0 2.2.2.2 10 UP
PE1#sh mpls l2 vc 10 detail
Local interface: CE0/4/32 up, line protocol up, CESoPSN Basic 0 up
Destination address: 2.2.2.2, VC ID: 10, VC status: up
Output interface: Te0/0/0, imposed label stack {650}
Preferred path: not configured
Default path: active
Next hop: 123.123.123.2
Create time: 00:21:25, last status change time: 00:21:25
Last label FSM state change time: 00:21:25
Signaling protocol: LDP, peer 2.2.2.2:0 up
Targeted Hello: 1.1.1.1(LDP Id) -> 2.2.2.2, LDP is UP
Graceful restart: configured and not enabled
Non stop routing: not configured and not enabled
Status TLV support (local/remote) : enabled/supported
LDP route watch : enabled
Label/status state machine : established, LruRru
Last local dataplane status rcvd: No fault
Last BFD dataplane status rcvd: Not sent
Last BFD peer monitor status rcvd: No fault
Last local AC circuit status rcvd: No fault
Last local AC circuit status sent: No fault
Last local PW i/f circ status rcvd: No fault
Last local LDP TLV status sent: No fault
Last remote LDP TLV status rcvd: No fault
Last remote LDP ADJ status rcvd: No fault
MPLS VC labels: local 577, remote 650
Group ID: local 238, remote 276
MTU: local 0, remote 0
Remote interface description:
Sequencing: receive disabled, send disabled
Control Word: On (configured: autosense)
SSO Descriptor: 2.2.2.2/10, local label: 577
Dataplane:
SSM segment/switch IDs: 6893171/4140658 (used), PWID: 674
VC statistics:
transit packet totals: receive 0, send 0
transit byte totals: receive 0, send 0
transit packet drops: receive 0, seq error 0, send 0
Configuring DS1 Local Connet
enable
configure terminal
controller T1 0/5/0
framing unframed
clock source internal
linecode b8zs
cablelength short 110
cem-group 0 unframed
description TO_CE1_0/1/0
enable
configure terminal
controller T1 0/5/3
framing unframed
clock source recovered 0
linecode b8zs
cablelength short 110
cem-group 0 unframed
description TO_CE1_0/1/1
The following section describes how to create a DS1 local connection:
enable
configure terminal
connect ds1_connect CEM0/5/0 0 CEM0/5/3 0
Verifying DS1 Local Connect
Use the following commands to verify the DS1 local connection:
-
show connection name—Displays information about the connection state and segment state.
Router#show connection name ds1_connect
Connection: 673 – ds1_connect
Current State: UP
Segment 1: CEM0/5/0 SATOP T1 0 up
Segment 2: CEM0/5/3 SATOP T1 0 up
Associated Commands
The following commands are used to configure pseudowire:
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Commands |
URL |
|---|---|
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cem-group |
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payload-size dejitter-buffer |
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class cem |
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controller t1 |
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xconnect |
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show controllers t3 |
Additional References for Configuring Pseudowire
Related Documents
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Related Topic |
Document Title |
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Cisco IOS commands |
Standards and RFCs
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Standard/RFC |
Title |
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There are no standards and RFCs for this feature. |
MIBs
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MIB |
MIBs Link |
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— |
To locate and download MIBs for selected platforms, Cisco IOS releases, and feature sets, use Cisco MIB Locator found at the following URL: |
Technical Assistance
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Description |
Link |
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The Cisco Support website provides extensive online resources, including documentation and tools for troubleshooting and resolving technical issues with Cisco products and technologies. To receive security and technical information about your products, you can subscribe to various services, such as the Product Alert Tool (accessed from Field Notices), the Cisco Technical Services Newsletter, and Really Simple Syndication (RSS) Feeds. Access to most tools on the Cisco Support website requires a Cisco.com user ID and password. |
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