Interface and Hardware Component Configuration Guide for Cisco ASR 9000 Series Routers, IOS XR Release 6.9.x
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This module describes the configuration of Circuit Emulation over Packet (CEoP) shared port adapters (SPAs) on the Cisco ASR 9000 Series Aggregation Services Routers.
Feature History for Configuring CEoP on Cisco ASR 9000 Series Router
Release
Modification
Release 4.2.0
Support for Circuit Emulation Service over Packet Switched Network was added in this SPA:
This module describes the configuration of Circuit Emulation over Packet (CEoP) shared port adapters (SPAs) on the Cisco ASR 9000 Series Aggregation Services Routers.
Feature History for Configuring CEoP on Cisco ASR 9000 Series Router
Release
Modification
Release 4.2.0
Support for Circuit Emulation Service over Packet Switched Network was added in this SPA:
You must be in a user group associated with a task group that includes the proper task IDs. The command reference guides include
the task IDs required for each command. If you suspect user group assignment is preventing you from using a command, contact
your AAA administrator for assistance.
Before configuring the Circuit Emulation over Packet (CEoP) service on your router, ensure that these conditions are met:
You must have one of these SPAs installed in your chassis:
Cisco 2-Port Channelized T3/E3 Circuit Emulation and Channelized ATM SPA
Cisco 24-Port Channelized T1/E1 Circuit Emulation and Channelized ATM SPA
Cisco 1-port Channelized OC3/STM-1 Circuit Emulation and ATM SPA
You should know how to apply and specify the SONET controller name and interface-path-id with the generalized notation rack/slot/module/port. The SONET controller name and interface-path-id are required with the controller sonet command.
You should know how to apply and specify the T3/E3 and T1/E1 controller name and interface-path-id with the generalized notation rack/slot/module/port. The T3/E3, T1/E1 controller name and interface-path-id are required with the controller {T3|E3|T1|E1} command.
Overview of Circuit Emulation over Packet Service
Circuit Emulation over Packet (CEoP) is a way to carry TDM circuits over packet switched network. Circuit Emulation over Packet
is an imitation of a physical connection. The goal of CEoP is to replace leased lines and legacy TDM networks. This feature
allows network administrators to use their existing IP or MPLS network to provide leased-line emulation services or to carry
data streams or protocols that do not meet the format requirements of other multiservice platform interfaces. CEoP puts TDM
bits into packets, encapsulates them into an appropriate header and then sends that through PSN. The receiver side of CEoP
restores the TDM bit stream from packets.
CEoP SPAs are half-height (HH) Shared Port Adapters (SPA) and the CEoP SPA family consists of 24xT1/E1/J1, 2xT3/E3, and 1xOC3/STM1
unstructured and structured (NxDS0) quarter rate, half height SPAs. The CEoP SPAs provide bit-transparent data transport that
is completely protocol independent.
CEoP has two major modes:
Unstructured mode is called SAToP (Structure Agnostic TDM over Packet) — SAToP does not look what is inside the incoming data
and considers it as a pure bit stream.
Structured mode is named CESoPSN (Circuit Emulation Service over Packet Switched Network) — CESoPSN is aware of the structure
of the incoming TDM bit stream at DS0 level.
CESoPSN and SAToP can use MPLS, UDP/IP, and L2TPv3 for the underlying transport mechanism.
Note
The Cisco IOS XR Release 4.2.x supports only MPLS transport mechanism.
These SPAs are the first Cisco router interfaces designed to meet the emerging standards for Circuit Emulation Services over
Packet Switched Network (CESoPSN) and Structure-Agnostic Transport over Packet (SAToP) transport.
In SAToP mode, these SPAs do not assume that data has any predefined format or structure. They simply regard the data as an
arbitrary bit stream. All data bits are simply transported to a defined destination encapsulated in IP/MPLS packets. In CESoPSN
mode the carrier has defined format. The SPAs support a full range of E1 and T1 framing. CESoPSN applications can save utilized
bandwidth by selecting only valid timeslots for transmission. Some primary applications include:
Transporting 2G and 3G network traffic over packet networks, for mobile operators. Mobile service providers are implementing
high-speed data networks with HSDPA to support new revenue-generating services. The SPA is uniquely positioned for multigenerational
migration of mobile networks (2G and 3G), simultaneously carrying TDM and ATM traffic over IP/MPLS networks. This technology
provides a mechanism to enable IP/MPLS to the cell site, which can eventually be in place to transport the mobile traffic
over IP from end to end.
T3/E3 circuit emulation for leased-line replacement.
T1/E1 circuit emulation for leased-line replacement.
PBX to PBX connectivity over PSN.
High density SS7 backhaul over IP/MPLS.
Inter-MSC connectivity.
Preencrypted data for government, defense, or other high-security applications.
Proprietary synchronous or asynchronous data protocols used in transportation, utilities, and other industries.
Leased-line emulation service offerings in metropolitan (metro) Ethernet or WAN service provider environments.
For more information on Circuit Emulation service concepts, configuration, and example, see the Implementing Point to Point Layer 2 Services module in the Cisco ASR 9000 Series Aggregation Services Router L2VPN and Ethernet Services Configuration Guide.
Information About Configuring CEoP Channelized SONET/SDH
To configure the Circuit Emulation over Packet Channelized SONET/SDH, you must understand the following concepts:
Channelized SONET
and SDH Overview
Synchronous Optical Network (SONET) is an American National
Standards Institute (ANSI) specification format used in transporting digital
telecommunications services over optical fiber.
Channelized SONET provides the ability to transport SONET frames
across multiplexed T3/E3 and virtual tributary group (VTG) channels.
SONET uses Synchronous Transport Signal (STS) framing. An STS is
the electrical equivalent to an optical carrier 1 (OC-1).
A channelized SONET interface is a composite of STS streams,
which are maintained as independent frames with unique payload pointers. The
frames are multiplexed before transmission.
When a line is channelized, it is logically divided into smaller
bandwidth channels called
paths. These paths carry the SONET payload. The sum of the
bandwidth on all paths cannot exceed the line bandwidth.
When a line is not channelized, it is called
clear channel, and the full bandwidth of the line is
dedicated to a single channel that carries broadband services.
The T3/E3 channels can be
channelized into T1s, and the T1s can be channelized further into DS0 time
slots.
Channelizing a SONET line consists of two primary processes:
Configuring the controller
Configuring the interface into channelized paths
You configure the controller first by setting the mode of the
STS path.
When the mode is specified, the respective controller is
created, and the remainder of the configuration is applied on that controller.
For example, mode T3 creates a T3 controller. The T3 controller can then be
configured to a serial channel, or it can be further channelized to carry T1s,
and those T1s can be configured to serial interfaces.
Depending on the support for
your installed SPA, each STS path can be independently configured into T3s,
E3s, or VTGs, and so on.
The following level of SONET channelization modes are supported
in CEoP SPA:
OC3->STS-1->VTG-> VT1.5 -> Unframed T1
OC3->STS-1->VTG-> VT1.5 -> T1 -> DS0
This figure shows the VTG paths that can be configured.
Note
Only VTG paths are supported on the Cisco 1-Port Channelized
OC-3/STM-1 SPA on the
Cisco ASR 9000 Series Router.
Synchronous Digital Hierarchy
(SDH) is the international equivalent of SONET.
SDH uses Synchronous
Transport Mode (STM) framing. An STM-1 is the electrical equivalent to 3
optical carrier 1s (OC-1s). A Synchronous Transport Module (STM) signal is the
Synchronous Digital Hierarchy (SDH) equivalent of the SONET STS, but the
numbers are different for each bandwidth. In this guide, the STM term refers to
both path widths and optical line rates. The paths within an STM signals are
called administrative units (AUs).
A summary of the basic
terminology differences between SONET and SDH is as follows:
SONET STS is equivalent to SDH administrative unit (AU)
SONET VT is equivalent to SDH tributary unit (TU)
SDH basic building blocks are STM-1 (equivalent to STS-3) and
STM-0 (equivalent to STS-1)
An administrative unit (AU)
is the information structure that provides adaptation between the higher-order
path layer and the multiplex section layer. It consists of an information
payload (the higher-order virtual container) and an administrative unit
pointer, which indicates the offset of the payload frame start relative to the
multiplex section frame start.
An AU can be channelized into
tributary units (TUs) and tributary unit groups (TUGs).
An administrative unit 3
(AU-3) consists of one STM-1.
An administrative unit group
(AUG) consists of one or more administrative units occupying fixed, defined
positions in an STM payload.
This table shows the commonly used notations and terms in SONET
standards and their SDH equivalents.
Table 1. SONET and SDH Terminology Equivalencies
SONET Term
SDH Term
SONET
SDH
STS-3c
AU-4
STS-1
AU-3
VT
TU
SPE
VC
Section
Regenerator Section
Line
Multiplex Section
Path
Path
The following levels of SDH
channelization are supported on the CEoP SPA:
Clocking distribution in the CEoP SPA can be done in these ways:
Synchronous Clocking — With synchronous clocking, TDM lines on
source and destination are synchronized to the same clock delivered by some
means of physical clock distribution (SONET/SDH, BITS, GPS, and so on). The
clock to the particular TDM line can be delivered from
Line: the transmit clock is from the receiver of the same
physical line
Internal: the transmit clock is taken from line card and can be
derived either from an internal free running oscillator or from another
physical line
Recovered: In-band pseudowire-based activeclock recovery on a
CEM interface which is used to drive the transmit clock.
The number of recovered clocks that can be configured for CEoP
SPA are:
Cisco 24-Port Channelized T1/E1 Circuit Emulation and
Channelized ATM SPA : 24 clocks for each SPA.
Cisco 2-Port Channelized T3/E3 Circuit Emulation and Channelized
ATM SPA : 10 clocks for each SPA in the T1/E1 mode and 2 clocks for each SPA in
the T3/E3 mode.
Cisco 1-port Channelized OC3/STM-1 Circuit Emulation and
Channelized ATM SPA : 10 clocks per SPA in the T1/E1 mode.
Adaptive Clocking — Adaptive clocking is used when the routers
do not have a common clock source. See this figure. The clock is derived based
on packet arrival rates. Two major types of adaptive clock recovery algorithms
are:
Based on dejitter buffer fill level
Based on packet arrival rate
The clock quality depends on packet size, has less tolerance to
packet loss/corruption and introduces unnecessary delay in order to have
sufficient number of packets in the buffer for clock recovery. The dejitter
buffer size determines the ability of the emulated circuit to tolerate network
jitter. The dejitter buffer in CEoP software is configurable up to a maximum of
500 milliseconds.
Note
The CEoP SPA hardware supports only the packet arrival rate
algorithm.
Figure 3. Adaptive Clock Recovery
Differential clocking — Differential clocking is used when the cell site and aggregation routers have a common clock source
but TDM lines are clocked by a different source. The TDM clocks are derived from differential information in the RTP header
of the packet with respect to the common clock. Differential clock recovery is based on time stamps received in RTP header.
On the reference clock side, the difference of TDM clock and network clock is recorded into RTP header. On the subordinate
clock side, these timestamps are read from RTP header, the clock recovery is done and this clock is used for synchronization.
See Figure 5.
Note
The Cisco 1-port Channelized OC3/STM-1 CEoP SPA hardware can
recover only a maximum of ten unique clocks in as many CEM interfaces. The CEM
interfaces where clock recovery is configured must be on unique T1s.
For information on CEM
configuration and commands, see
Implementing Point to Point Layer 2 Services module in the
Cisco ASR 9000 Series Aggregation Services Router L2VPN and
Ethernet Services Configuration Guide
and Cisco ASR 9000 Series Aggregation Services Router L2VPN and
Ethernet Services Command Reference.
SONET framing (sonet) is the default. Whenever there is a
change in framing mode (sonet/sdh), the SPA will be reloaded automatically.
Reload will happen only when all the CEM Interface, T1 Controller and Sonet
Controller configurations are removed completely. This is not applicable when
you configure the first time because T1 controller and interface configurations
would not exist.
This configuration is mandatory for CEoP SPA
to work normally in one of the framing modes. When you configure for the first
time, it will not cause a SPA reload, if the cardtype is set to Sonet.
Step 3
commit
Use the
commit command to
save the configuration changes to the running configuration file and remain
within the configuration session.
Step 4
controller
sonet
interface-path-id
Enters controller configuration submode and
specifies the SONET controller name and instance identifier with the
rack/slot/module/port/controllerName
notation.
Step 5
stsnumber
Example:
RP/0/RSP0/CPU0:router(config-sonet)# sts 1
Configures the STS stream specified by
number. The range
is from1 to 3.
Step 6
modemode
Example:
RP/0/RSP0/CPU0:router(config-stsPath)# mode t1
Sets the mode of interface at the STS level.
The possible modes are:
Exits to global configuration mode. Go to
step 7, if you want to create an structure agnostic CEM interface. Go to step
9, if you want to create a structure aware CEM interface.
Enters T1 controller configuration submode
and specifies the T1 controller name and
interface-path-id
with the
rack/slot/module/port/sts-num/vtg-num/T1-num
notation.
Enters T1 controller configuration submode
and specifies the T1 controller name and
interface-path-id
with the
rack/slot/module/port/sts-num/vtg-num/T1-num
notation.
Creates an structure aware CEM interface.
The
timeslots keyword
specifies the time slots for the interface by range with the
range1-range2
notation.
Step 12
no
shutdown
Example:
RP/0/RSP0/CPU0:router(config-if)# no shutdown
Removes the shutdown configuration.
Note
Removal of the shutdown configuration
eliminates the forced administrative down on the interface, enabling it to move
to an up or down state (assuming that the parent SONET layer is not configured
administratively down).
Step 13
end
or
commit
Example:
RP/0/0RSP0/CPU0:router(config-sonet)# end
or
RP/0/RSP0/CPU0:router(config-sonet)# commit
Saves configuration changes.
When you issue the
end command,
the system prompts you to commit changes:
Uncommitted changes found, commit them before exiting(yes/no/cancel)?
[cancel]:
Entering
yes
saves configuration changes to the running configuration
file, exits the configuration session, and returns the router to EXEC mode.
Entering
no exits the configuration session
and returns the router to EXEC mode without committing the configuration
changes.
Entering
cancel leaves the router in the
current configuration session without exiting or committing the configuration
changes.
Use the
commit command
to save the configuration changes to the running configuration file and remain
within the configuration session.
Step 14
show runn
interface ceminterface-path-id
Example:
RP/0/RSP0/CPU0:router# show runn interface cem 0/0/2/0/1/1/1/1:1
Verifies the CEM interface configuration.
Configuring SDH AU-3 Mapped to C11-T1 or C12-E1
This section includes the following tasks:
Configuring SDH AU-3 Mapped to C11-T1 and Creating CEM
Interface
This task explains how to configure SDH AU-3
with c11-t1 mapping.
Before you begin
You should know how to configure the
SONET/SDH controller.
Restrictions
Channelized SDH AU-3 with c11-t1 mapping is
supported on this SPA:
Configures the controller for Synchronous
Digital Hierarchy (SDH) framing. The
hw-module subslotnode-idcardtypetype command configures
the SPA to function in sonet/sdh mode.
This command when committed results in
automatic reload of SPA. Reload happens only when all the CEM interface, T1
Controller and Sonet Controller configurations are removed completely. This is
not applicable when you configure the first time because T1 controller and
interface configurations would not exist.
This configuration is mandatory for CEoP SPA
to work normally in one of the framing modes. SONET framing (sonet) is the default.
Step 3
commit
Use the
commit command to
save the configuration changes to the running configuration file and remain
within the configuration session.
Step 4
controller
sonet
interface-path-id
Enters controller configuration submode and
specifies the SDH controller name and instance identifier with the
rack/slot/module/port/controllerName
notation.
Step 5
aunumber
Example:
RP/0/RSP0/CPU0:router(config-sonet)# au 1
Specifies the administrative unit (AU) group
and enters AU path configuration mode. For AU-3, the valid range is:
1 to 3—1-Port Channelized OC-3/STM-1 SPA
Note
The
au command does not specify
the AU type. It specifies the number of the AU group for the AU type that you
want to configure. The range for the AU command varies based on whether you are
configuring AU-3 or AU-4.
Step 6
modemode
Example:
RP/0/RSP0/CPU0:router(config-auPath)# mode c11-t1
Sets the mode of interface at the AU level.
AU-3 paths can be mapped to c11-t1 on supported SPAs.
Enters T1 controller configuration submode
and specifies the T1 controller name and
interface-path-id
with the
rack/slot/module/port/auNum/t1Num
notation.
Enters T1 controller configuration submode
and specifies the T1 controller name and
interface-path-id
with the
rack/slot/module/port/auNum/t1Num
notation.
Creates an structure aware CEM interface.
The
timeslots keyword
specifies the time slots for the interface by range with the
range1-range2
notation.
Step 12
no
shutdown
Example:
RP/0/RSP0/CPU0:router(config-if)# no shutdown
Removes the shutdown configuration.
Note
Removal of the shutdown configuration
eliminates the forced administrative down on the interface, enabling it to move
to an up or down state (assuming that the parent SONET layer is not configured
administratively down).
Step 13
end
or
commit
Example:
RP/0/RSP0/CPU0:router(config-sonet)# end
or
RP/0/RSP0/CPU0:router(config-sonet)# commit
Saves configuration changes.
When you issue the
end command,
the system prompts you to commit changes:
Uncommitted changes found, commit them before exiting(yes/no/cancel)?
[cancel]:
Entering
yes saves configuration changes to
the running configuration file, exits the configuration session, and returns
the router to EXEC mode.
Entering
no exits the configuration session
and returns the router to EXEC mode without committing the configuration
changes.
Entering
cancel leaves the router in the
current configuration session without exiting or committing the configuration
changes.
Use the
commit command
to save the configuration changes to the running configuration file and remain
within the configuration session.
Step 14
show runn
interface ceminterface-path-id
Example:
RP/0/RSP0/CPU0:router# show runn interface cem 0/0/2/0/1/1/1/1:1
Verifies the CEM interface configuration.
Configuring SDH AU-3 Mapped to C12-E1 and Creating CEM
Interface
This task explains how to configure SDH AU-3
with c12-e1 mapping.
Before you begin
You should know how to configure the
SONET/SDH controller.
Restrictions
Channelized SDH AU-3 with c12-e1 mapping is
supported on this SPA:
Configures the controller framing for
Synchronous Digital Hierarchy (SDH) framing. The
hw-module subslotnode-idcardtypetype command configures
the SPA to function in sonet/sdh mode. This command when committed results in
automatic reload of SPA. Reload happens only when all the CEM interface, E1
Controller and Sonet Controller configurations are removed completely.
Step 3
commit
Use the
commit command to
save the configuration changes to the running configuration file and remain
within the configuration session.
Step 4
controller
sonet
interface-path-id
Enters controller configuration submode and
specifies the SDH controller name and instance identifier with the
rack/slot/module/port/controllerName
notation.
Step 5
aunumber
Example:
RP/0/RSP0/CPU0:router(config-sonet)# au 1
Specifies the administrative unit (AU) group
and enters AU path configuration mode. For AU-3, the valid range is:
1 to 3—1-Port Channelized OC-3/STM-1 SPA
Note
The
au command does not specify
the AU type. It specifies the number of the AU group for the AU type that you
want to configure. The range for the AU command varies based on whether you are
configuring AU-3 or AU-4.
Step 6
mode
tug3
Example:
RP/0/RSP0/CPU0:router(config-auPath)# mode tug3
Sets the mode of interface at the AU level.
Currently only TUG3 is supported.
Step 7
widthnumber
Example:
RP/0/RSP0/CPU0:router(config-auPath)# width 3
Configures the number of the AU streams.
Step 8
tug3number
Example:
RP/0/RSP0/CPU0:router(config-auPath)#tug3 1
Specifies the Tributary Unit Group (TUG)
number and enters
the config-tug3Path mode. The range is 1 to 3.
Enters E1 controller configuration submode
and specifies the E1 controller name and
interface-path-id
with the
rack/slot/module/port/auNum/tugNum/t1Num
notation.
Enters E1 controller configuration submode
and specifies the E1 controller name and
interface-path-id
with the
rack/slot/module/port/auNum/tugNum/t1Num
notation.
Removal of the shutdown configuration
eliminates the forced administrative down on the interface, enabling it to move
to an up or down state (assuming that the parent SONET layer is not configured
administratively down).
Step 16
end
or
commit
Example:
RP/0/RSP0/CPU0:router(config-sonet)# end
or
RP/0/RSP0/CPU0:router(config-sonet)# commit
Saves configuration changes.
When you issue the
end command,
the system prompts you to commit changes:
Uncommitted changes found, commit them before exiting(yes/no/cancel)?
[cancel]:
Entering
yes saves configuration changes to
the running configuration file, exits the configuration session, and returns
the router to EXEC mode.
Entering
no exits the configuration session
and returns the router to EXEC mode without committing the configuration
changes.
Entering
cancel leaves the router in the
current configuration session without exiting or committing the configuration
changes.
Use the
commit command
to save the configuration changes to the running configuration file and remain
within the configuration session.
Configuring the Cisco 24-Port Channelized T1/E1 Circuit Emulation and Channelized ATM SPA and Creating CEM Interface
This task explains how to configure the Cisco 24-Port Channelized T1/E1 Circuit Emulation and Channelized ATM SPA.
The hw-module subslotnode-idcardtypetype command configures the SPA to function in t1/e1 mode.
Reload will happen only when all the CEM interface, T1 Controller configurations are removed completely. This is not applicable
when you configure the first time because T1 controller and interface configurations would not exist.
Creates an structure aware CEM interface. The timeslots keyword specifies the time slots for the interface by range with the range1-range2 notation.
Step 7
no shutdown
Example:
RP/0/RSP0/CPU0:router(config-if)# no shutdown
Removes the shutdown configuration.
Note
Removal of the shutdown configuration eliminates the forced administrative down on the interface, enabling it to move to an
up or down state.
Step 8
end
or
commit
Example:
RP/0/RSP0/CPU0:router(config-t1)# end
or
RP/0/RSP0/CPU0:router(config-t1)# commit
Saves configuration changes.
When you issue the end command, the system prompts you to commit changes:
Uncommitted changes found, commit them before exiting(yes/no/cancel)?
[cancel]:
Entering yes saves configuration changes to the running configuration file, exits the configuration session, and returns the router to
EXEC mode.
Entering no exits the configuration session and returns the router to EXEC mode without committing the configuration changes.
Entering cancel leaves the router in the current configuration session without exiting or committing the configuration changes.
Use the commit command to save the configuration changes to the running configuration file and remain within the configuration session.
Step 9
show runn interface ceminterface-path-id
Example:
RP/0/RSP0/CPU0:router# show runn interface cem 0/0/2/0/1:1
Verifies the CEM interface configuration.
Configuring the Cisco 2-Port Channelized T3/E3 Circuit Emulation and Channelized ATM SPA and Creating CEM Interface
T3/E3 Channelization Mode
This task explains how to configure the Cisco 2-Port Channelized T3/E3 Circuit Emulation and Channelized ATM SPA using T3
channelization.
Note
The T3 channels can be channelized into T1s or E1s, and the T1s or E1s can be channelized further into DS0 time slots, on
the Cisco 2-Port Channelized T3/E3 Circuit Emulation and Channelized ATM SPA.
SUMMARY STEPS
configure
hw-module subslot node-id cardtype {t3| e3}
commit
controller {t3|e3}interface-path-id
cem-group unframed
no shutdown
end
or
commit
show runn interface ceminterface-path-id
DETAILED STEPS
Command or Action
Purpose
Step 1
configure
Example:
RP/0/RSP0/CPU0:router# configure
Enters global configuration mode.
Step 2
hw-module subslot node-id cardtype {t3| e3}
Example:
RP/0/RSP0/CPU0:router(config-t3)# hw-module subslot 0/3/0 cardtype t3
The hw-module subslotnode-idcardtypetype command configures the SPA to function in t3/e3 mode.
Whenever there is a change in framing mode (t3/e3), the SPA will be reloaded automatically. Reload will happen only when all
the CEM Interface, T3 Controller configurations are removed completely. This is not applicable when you configure the first
time because T3 controller and interface configurations would not exist.
Step 3
commit
Use the commit command to save the configuration changes to the running configuration file and remain within the configuration session.
Step 4
controller {t3|e3}interface-path-id
Example:
RP/0/RSP0/CPU0:router(config)# controller t3 0/0/1/0/4
Enters T3/E3 controller configuration submode and specifies the T3/E3 controller name and interface-path-id with the rack/slot/module/port/T3Num notation.
RP/0/RSP0/CPU0:router(config-sonet)# hw-module subslot 0/3/0 t3
The hw-module subslotnode-idcardtypetype command configures the SPA to function in t3/e3 mode.
Whenever there is a change in framing mode (t3/e3), the SPA will be reloaded automatically. Reload will happen only when all
the CEM Interface, T3 Controller configurations are removed completely. This is not applicable when you configure the first
time because T3 controller and interface configurations would not exist.
Step 3
commit
Use the commit command to save the configuration changes to the running configuration file and remain within the configuration session.
Step 4
controller t3interface-path-id
Example:
RP/0/RSP0/CPU0:router(config)# controller t3 0/0/1/0/4
Enters T3 controller configuration submode and specifies the T3 controller name and interface-path-id with the rack/slot/module/port/T3Num notation.
Step 5
mode {t1|e1}
Sets the mode of interface. The possible modes are T1 and E1 channelization mode.
Enters T1 controller configuration submode and specifies the T1 controller name and interface-path-id with the rack/slot/module/port/T3Num/T1num notation.
Enters T1 controller configuration submode and specifies the T1 controller name and interface-path-id with the rack/slot/module/port/T3Num/T1num notation.
Creates an structure aware CEM interface. The timeslots keyword specifies the time slots for the interface by range with the range1-range2 notation.
Step 10
no shutdown
Example:
RP/0/RSP0/CPU0:router(config-if)# no shutdown
Removes the shutdown configuration.
Note
Removal of the shutdown configuration eliminates the forced administrative down on the interface, enabling it to move to an
up or down state.
Step 11
end
or
commit
Example:
RP/0/RSP0/CPU0:router(config-t1)# end
or
RP/0/RSP0/CPU0:router(config-t1)# commit
Saves configuration changes.
When you issue the end command, the system prompts you to commit changes:
Uncommitted changes found, commit them before exiting(yes/no/cancel)?
[cancel]:
Entering yes saves configuration changes to the running configuration file, exits the configuration session, and returns the router to
EXEC mode.
Entering no exits the configuration session and returns the router to EXEC mode without committing the configuration changes.
Entering cancel leaves the router in the current configuration session without exiting or committing the configuration changes.
Use the commit command to save the configuration changes to the running configuration file and remain within the configuration session.
Step 12
show runn interface ceminterface-path-id
Example:
RP/0/RSP0/CPU0:router# show runn interface cem 0/0/2/0/1/1/1/1:1
Verifies the CEM interface configuration.
Configuring CEM Interface
This section provides information about how to configure CEM. CEM provides a bridge between a time-division multiplexing (TDM)
network and a packet network using Multiprotocol Label Switching (MPLS). The router encapsulates the TDM data in the MPLS
packets and sends the data over a CEM pseudowire to the remote provider edge (PE) router.
The following sections describe how to configure CEM:
Configuration Guidelines and Restrictions
All combinations of payload size and dejitter buffer size are not supported. If you apply an incompatible payload size or
dejitter buffer configuration, the router rejects it and reverts to the previous configuration.
Configuring a Global CEM Class
This task explains how to configure a global CEM class.
Note
Any interface configuration would have higher precedence over
configuration applied through attaching a CEM class. Also, CEM class attached
to an interface would have higher precedence than CEM class attached to the
parent controller. For example, if the dummy pattern value of
0xcf is applied directly to an
interface and then a CEM class which contains dummy pattern value of
0xaa is attached to the same
interface, then the dummy pattern value would be
0xcf. The new configuration would not
be applied until the dummy pattern value applied directly to the interface is
removed.
Specifies the CEM interface or the T1/E1
controller.
Step 5
cem
class-attach
class-name
Example:
RP/0/RSP0/CPU0:router(config)# cem class-attach Default
Attaches the CEM class to an interface or
controller.
Step 6
end or
commit
Example:
RP/0/RSP0/CPU0:router(config-cem-class)# end
or
RP/0/RSP0/CPU0:router(config-cem-class)# commit
Saves configuration changes.
When you issue the
end command,
the system prompts you to commit changes:
Uncommitted changes found, commit them before exiting(yes/no/cancel)?
[cancel]:
Entering
yes saves configuration changes to
the running configuration file, exits the configuration session, and returns
the router to EXEC mode.
Entering
no exits the configuration session
and returns the router to EXEC mode without committing the configuration
changes.
Entering
cancel leaves the router in the
current configuration session without exiting or committing the configuration
changes.
Use the
commit command
to save the configuration changes to the running configuration file and remain
within the configuration session.
Configuring Payload Size
To specify the number of bytes encapsulated into a single IP packet, use the cem payload 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:
E1 = 256 bytes
T1 = 192 bytes
E3 = 1024 bytes
T3 = 1024 bytes
Default payload sizes for a structured CEM channel depend on the number of time slots that constitute the channel. Payload
(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 calculated using the packetization latency depending on the number of time slots the cem interface
represents. The relationship between the number of time slots and the packetization latency is provided below:
For N = 1, D is 8 milliseconds (with the corresponding packet payloadsize of 64 bytes)
For 2 <=N <= 4, D is 4 milliseconds (with the corresponding packetpayload size of 32*N bytes)
For N >= 5, D is 1 millisecond (with the corresponding packet payloadsize of 8*N octets).
Support of 5 ms packetization latency for N = 1 is recommended.
Setting the Dejitter Buffer Size
To specify the size of the dejitter buffer used to compensate for the network filter, use the cem dejitter 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 500 ms.
The following is an example:
Router(config-cem)# cem dejitter 5
The default dejitter buffer for a CEM channel, irrespective of CESoPSN or SAToP, is as follows:
E1 = 16 milliseconds
T1 = 16 milliseconds
E3 = 5 milliseconds
T3 = 5 milliseconds
Note
Refer the T1/E1 SAToP lines:Payload and jitter limits table, the T3/E3 SAToP lines:Payload and jitter limits table, and the
ICESoPSN DSo lines:Payload and jitter limits table for the relationship between payload and dejitter buffer on SAToP T1/E1,
T3/E3, and CESoPSN lines. Configuration of payload and dejitter should be in accordance with the minimum and maximum values
as mentioned in the table.
The maximum and minimum dejitter buffer value, that is the range is fixed for a given payload value.
Setting an Idle Pattern
To specify an idle pattern, use the [no] cem idle pattern pattern command. The payload of each lost CESoPSN data packet must be replaced with the equivalent amount of the replacement data.
The range for pattern is from 0x0 to 0xff; the default idle pattern is 0xff. This is an example:
Router(config-cem)# cem idle pattern 0xff
If the expected CEM packets are not received for a given CEM interface and are considered as being lost, then the CEoP SPA
will play out the idle pattern towards the TDM attachment circuit in the respective timeslots configured in the CEM group.
Enabling Dummy Mode
Dummy mode enables a bit pattern for filling in for lost or corrupted frames. To enable dummy mode, use the cem dummy mode [last-frame | user-defined] command. The default is last-frame. This is an example:
Router(config-cem)# cem dummy mode last-frame
When packets are lost due to misordering or where reordering of packets is not successful, the CEoP SPA will play out the
Dummy pattern towards the TDM attachment circuit in respective timeslots configured in the CEM group.
Setting a Dummy Pattern
If dummy mode is set to user-defined, you can use the cem dummy-pattern command to configure the dummy pattern. The range for pattern is from 0x0 to 0xff. The default dummy pattern is 0xff. This
is an example:
Router(config-cem)# cem dummy-pattern 0xff
This Table shows the relationship between payload and dejitter for T1/E1 SAToP lines.
T1/E1 SAToP lines: Payload and Jitter Limits
Table 3.
T1/E1
Maximum Payload
Maximum Jitter
Minimum Jitter
Minimum Payload
Maximum Jitter
Minimun Jitter
T1
960
320
10
192
64
2
E1
1280
320
10
256
64
2
This table shows the relationship between payload and dejitter for T3/E3 SAToP lines.
T3/E3 SAToP lines: Payload and Jitter Limits
Table 4.
T3/E3
Maximum Payload
Maximum Jitter
Minimum Jitter
Minimum Payload
Maximum Jitter
Minimun Jitter
T3
1312
8
2
672
8
2
E3
1312
16
2
512
8
2
This table shows the relationship between payload and dejitter for DS0 lines.
CESoPSN DS0 Lines: Payload and Jitter Limits
Table 5.
DS0
Maximum Payload
Maximum Jitter
Minimum Jitter
Minimum Payload
Maximum Jitter
Minimun Jitter
1
40
320
10
32
256
8
2
80
320
10
32
128
4
3
120
320
10
33
128
4
4
160
320
10
32
64
2
5
200
320
10
40
64
2
6
240
320
10
48
64
2
7
280
320
10
56
64
2
8
320
320
10
64
64
2
9
360
320
10
72
64
2
10
400
320
10
80
64
2
11
440
320
10
88
64
2
12
480
320
10
96
64
2
13
520
320
10
104
64
2
14
560
320
10
112
64
2
15
600
320
10
120
64
2
16
640
320
10
128
64
2
17
680
320
10
136
64
2
18
720
320
10
144
64
2
19
760
320
10
152
64
2
20
800
320
10
160
64
2
21
840
320
10
168
64
2
22
880
320
10
176
64
2
23
920
320
10
184
64
2
24
960
320
10
192
64
2
25
1000
320
10
200
64
2
26
1040
320
10
208
64
2
27
1080
320
10
216
64
2
28
1120
320
10
224
64
2
29
1160
320
10
232
64
2
30
1200
320
10
240
64
2
31
1240
320
10
248
64
2
32
1280
320
10
256
64
2
Configuring Clocking
Each SPA port shall be configured either to use system clock from the host card or loop timed independently. Each SPA also
supplies a reference clock to the host which can be selected among the received port clocks. This section provides information
about how to configure clocking on the 1xOC3 SPA.
This section describes the following topics:
Configuring Clock Recovery
When configuring clock recovery, consider the following guidelines:
Adaptive Clock Recovery
Clock source:
In Cisco IOS XR Release 4.2.x and later, recovered clock from a CEM interface on the 1-Port Channelized OC-3/STM1 CEoP SPA
can be used as a clock source on the SPA itself.
The clock must be the same as used by the router as the network clock. Any pseudowire in this case can carry the clock.
The minimum bundle size of CEM pseudowires on the network that delivers robust clock recovery is 4 DS0s.
The minimum packet size of CEM pseudowires on the network that delivers robust clock recovery is 64 bytes.
Differential Clocking
The maximum number of differential clocks sourced from a 1-Port Channelized OC-3/STM1 CEoP SPA is 10.
The 1-Port Channelized OC-3/STM1 CEoP SPA can recover up to 10 T1/E1 clocks.
There are several bundles sent from the same port. The bundle that is used for carrying the clock of the port is the first
created bundle of the port. Only pseudowires that include the first DS0 of a port can carry differential clock.
You must have a Stratum-1 clock, a common clock going to both PE routers. If not, the recovery will not work as expected.
To configure clock recovery on the CEoP SPA and to apply the recovered clock to the controller, use the following procedure:
SUMMARY STEPS
configure
interface cem rack/slot/subslot/port:cem-group
transmit-clock {differential}
recover-clock clock-id {adaptive | differential}
controllernameinstance
clock source recovered clock-id
DETAILED STEPS
Command or Action
Purpose
Step 1
configure
Example:
RP/0/RSP0/CPU0:router# configure
Enters global configuration mode.
Step 2
interface cem rack/slot/subslot/port:cem-group
Example:
RP/0/RSP0/CPU0:router(config)# interface cem 0/1/0/0:2
Configures the CEM port transmit clock source. This is typically configured at the node acting as primary to send the clock.
This command is not required for Adaptive Clock Recovery.
Specifies the recovered clock number and the clock recovery type. This is typically configured at the node acting as subordinate
that recovers the clock from incoming CEM packets from core.
Enters controller configuration submode and specifies the controller name and instance identifier with the rack/slot/module/port/name/instance1/instance2 notation.
Specifies the recovered clock number. This applies the recovered clock from a CEM interface on a T1/E1 Controller.
Verifying Clock recovery
To verify clock recovery, use the show recovered-clock command.
Router# show recovered-clock sublsot 0/3/0
Recovered clock status for subslot 0/3/0
----------------------------------------
Clock Mode Port CEM Status Frequency Offset(ppb)
1 ADAPTIVE 0 1 HOLDOVER 0
Router# show recovered-clock
Recovered clock status for subslot 3/0
----------------------------------------
Clock Mode Port CEM Status Frequency Offset(ppb)
1 ADAPTIVE 0 1 ACQUIRING -694
Show Commands for CEM
You can use the command show controller cem<forward interface instance> to verify the CEM parameter information. The following example provides a sample output for the command.
Ouput of show controller cem forward interface instance command
RP/0/RSP0/CPU0:Router# show controllers cem 0/4/1/0:0
Interface : CEM0/4/1/0:0
Admin state : Up
Driver link state : Up
Port bandwidth(kbps) : 1984
Dejitter buffer : 16
Payload size : 248
Dummy mode : last-frame
Dummy pattern : 0xff
Idle pattern : 0xff
Signalling : No CAS
RTP : Enabled
Ingress packets : 1638960097, Ingress packets drop : 0
Egress packets : 1207954294, Egress packets drop : 287140468
Missing packets : 160475876, Reordered packets : 50092
Malformed packets : 73, Misorder drops : 7
Jitter buffer underrun : 28, Error seconds : 79673
Severely error seconds : 25721, Unavailable seconds : 160361
Failure counts : 2
SDH - E1 Channelization and CEM Interface Creation
hw-module subslot <loc> cardtype sdh
controller SONET 0/0/2/0
au 1
mode tug3
width 3
tug3 1
mode c12-e1
tug3 2
mode c12-e1
tug3 3
mode c12-e1
commit
In case of structure agnostic cem interface:
controller E1 0/0/2/0/1/1/1/1
cem-group unframed
In case of structure aware cem interface:
controller E1 0/0/2/0/1/1/7/1
cem-group framed 0 timeslots 1
cem-group framed 1 timeslots 2-3
cem-group framed 2 timeslots 4-6
cem-group framed 3 timeslots 7-10
cem-group framed 4 timeslots 11-15
cem-group framed 5 timeslots 16-21
cem-group framed 6 timeslots 22-31
CEM Interface Configuration
RP/0/RSP0/CPU0:CEOP-01#show runn interface cem 0/0/2/0/1/1/1/1:1
interface CEM0/0/2/0/1/1/1/1:1
l2transport
!
CEM Interface Config Options :
RP/0/RSP0/CPU0:CEOP-01(config)#interface cem 0/0/2/0/1/1/1/1:1
RP/0/RSP0/CPU0:CEOP-01(config-if)#cem ?
class-attach Attach a CEM class to this interface
clock Configure clocks on this CEM interface
dejitter Configure dejitter buffer
dummy Configure dummy frame parameters
idle Configure idle frame parameters
payload Configure payload size of CEM frames
SAToP CEM interface creation on T3 / E3 on Cisco 2-Port Channelized T3/E3 Circuit Emulation and Channelized ATM SPA
RP/0/0/CPU0:router(config)#controller t3 0/4/2/0
RP/0/0/CPU0:router(config-t3)#cem-group ?
unframed clear channel carrying CEM
RP/0/0/CPU0:router(config-t3)#cem-group unframed
RP/0/0/CPU0:router(config-t3)#commit
RP/0/0/CPU0:router(config-t3)#
SAToP CEM interface creation on T1 / E1 on Cisco 2-Port Channelized T3/E3 Circuit Emulation and Channelized ATM SPA
RP/0/0/CPU0:router(config)#controller t3 0/4/2/0
RP/0/0/CPU0:router(config-t3)#mode ?
atm clear channel carrying atm
e1 channelize into 21 E1s
serial clear channel carrying hdlc like payload
t1 channelized into 28 T1s
RP/0/0/CPU0:router(config-t3)#mode e1
RP/0/0/CPU0:router(config-t3)#commit
RP/0/0/CPU0:router(config)#controller e1 0/4/2/0/1
RP/0/0/CPU0:router(config-e1)#cem-group ?
framed Configure a framed CEM interface on T1/E1
unframed Configure a unframed CEM interface on T1/E1
RP/0/0/CPU0:router(config-e1)#cem-group unframed ?
<cr>
RP/0/0/CPU0:router(config-e1)#cem-group unframed
RP/0/0/CPU0:router(config-e1)#commit
CESoPSN CEM interface creation on T1/E1 on Cisco 2-Port Channelized T3/E3 Circuit Emulation and Channelized ATM SPA
RP/0/0/CPU0:router(config)#controller t3 0/4/2/1
RP/0/0/CPU0:router(config-t3)#mode ?
atm clear channel carrying atm
e1 channelize into 21 E1s
serial clear channel carrying hdlc like payload
t1 channelized into 28 T1s
RP/0/0/CPU0:router(config-t3)#mode t1
RP/0/0/CPU0:router(config-t3)#commit
RP/0/0/CPU0:router(config)#controller t1 0/4/2/1/1
RP/0/0/CPU0:router(config-t1)#cem-group ?
framed Configure a framed CEM interface on T1/E1
unframed Configure a unframed CEM interface on T1/E1
RP/0/0/CPU0:router(config-t1)#cem-group framed ?
<0-23> CEM group number
RP/0/0/CPU0:router(config-t1)#cem-group framed 0 ?
timeslots List of timeslots in the CEM group
RP/0/0/CPU0:router(config-t1)#cem-group framed 0 timeslots ?
WORD timeslot string seprated by (:) or (-) from 1 to 24. (:) indicates individual timeslot and (-) represent range
RP/0/0/CPU0:router(config-t1)#cem-group framed 0 timeslots 1:23
RP/0/0/CPU0:router(config-t1)#commit
SAToP CEM interface creation on T1 / E1 on Cisco 24-Port Channelized T1/E1 Circuit Emulation and Channelized ATM SPA
RP/0/0/CPU0:router(config)#controller e1 0/4/1/2
RP/0/0/CPU0:router(config-e1)#cem-group ?
framed Configure a framed CEM interface on T1/E1
unframed Configure a unframed CEM interface on T1/E1
RP/0/0/CPU0:router(config-e1)#cem-group unframed ?
<cr>
RP/0/0/CPU0:router(config-e1)#cem-group unframed
RP/0/0/CPU0:router(config-e1)#commit
CESoPSN CEM interface creation on T1 / E1 on Cisco 24-Port Channelized T1/E1 Circuit Emulation and Channelized ATM SPA
RP/0/0/CPU0:router(config)#controller e1 0/4/1/1
RP/0/0/CPU0:router(config-e1)#cem-group framed ?
<0-30> CEM group number
RP/0/0/CPU0:router(config-e1)#cem-group framed 1 ?
timeslots List of timeslots in the CEM group
RP/0/0/CPU0:router(config-e1)#cem-group framed 1 timeslots ?
WORD timeslot string seprated by (:) or (-) from 1 to 31. (:) indicates individual timeslot and (-) represent range
RP/0/0/CPU0:router(config-e1)#cem-group framed 1 timeslots 1:20
RP/0/0/CPU0:router(config-e1)#commit
Clock Recovery: Example
Adaptive Clock Recovery Configuration:
(E1 configurations are similar to T1s given below)
CE1
----
Router (config)#controller t1 0/0/2/0/1/1/4
Router (config-t1)#clock source internal
PE1 (Acts as source of clock, but no specific configuration under CEM Interface is needed here)
----------------------------------------------------------------------------------------
Router (config)#controller t1 0/0/2/0/1/1/4
Router (config-t1)#clock source line
PE2 (On PE node where clock recovery is done):
----------------------------------------
To recover the adaptive clock:
Router(config)# interface cem 0/0/2/0/1/1/4:0
Router(config-if)#cem clock recover <clock-id> adaptive