Table Of Contents
OC-3/STM-1 ATM Circuit Emulation Service Network Module
Circuit Emulation Service Overview
Supported Standards, MIBs, and RFCs
Configuring Virtual Path Shaping
Configuring the T1/E1 Controller
Examples of CES Clock Configuration
Configuring Unstructured Circuit Emulation Service
Configuring Structured Circuit Emulation Service
Configuring Channel Associated Signaling for Structured CES
Monitoring and Maintaining the OC-3/STM-1 ATM Circuit Emulation Service Network Module
PVC-to-TDM CES Connection Example
Video Traffic Configuration Example
OC-3/STM-1 ATM Circuit Emulation Service Network Module
The following sections are provided:
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Supported Standards, MIBs, and RFCs
Feature Overview
This document describes how to configure the following 1-port OC-3/STM-1 ATM Circuit Emulation Service network modules with circuit emulation service for the Cisco 3600 series of modular access routers:
All modules provide connectivity to an OC-3/STM-1fiber for high-bandwidth data applications and voice-data integration applications. The circuit emulation service deck enables the network module to carry voice traffic, such as telephone calls and faxes, video, or any other legacy TDM traffic over an ATM network simultaneously with data traffic. The circuit emulation service deck supports ATM AAL1 structured and unstructured Circuit Emulation Service (CES). The circuit emulation service deck also supports echo cancellation for a full T1/E1 trunk, allowing digital ISDN calls and analog modem calls over a single digital network interface.
You need both an OC-3/STM-1 ATM Circuit Emulation Service network module and a 1- or 2-port T1 or E1 multiflex trunk interface card (VWIC-1MFT-T1=, VWIC-1MFT-E1=, VWIC-2MFT-T1=, VWIC-2MFT-E1=, VWIC-2MFT-T1-DI=, VWIC-2MFT-E1-DI=) for a voice connection. You can install one multiflex trunk interface card (providing up to two voice ports) in the circuit emulation service deck on the OC-3/STM-1 ATM Circuit Emulation Service network module. To install a multiflex trunk interface card in a network module, see the Cisco WAN Interface Cards Hardware Installation Guide publication.
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Circuit Emulation Service Overview
Circuit emulation is a service based on ATM Forum standards that allows communications to occur between AAL1 CES and ATM UNI interfaces, that is, between non-ATM telephony devices (such as classic PBXs or TDMs) and ATM devices (such as Cisco 3600 series routers). Thus, a Cisco 3600 series router equipped with an OC-3/STM-1 ATM Circuit Emulation Service network module offers a migration path from classic T1/E1 data communications service to emulated CES T1/E1 unstructured (clear channel) services or structured (N x 64) services in an ATM network.
Figure 1 shows a simplified representation of CES functions in an ATM network.
Figure 1 Typical CES-IWF Operations in an ATM Network
Circuit emulation service allows you to interconnect existing T1 or E1 interfaces and other kinds of constant bit rate (CBR) equipment. Circuit emulation service includes such features as PBX interconnect, consolidated voice and data traffic, and video conferencing.
With circuit emulation, data received from an external device at the edge of an ATM network is converted to ATM cells, sent through the network, reassembled into a bit stream, and passed out of the ATM network to its destination. T1/E1 circuit emulation does not interpret the contents of the data stream. All the bits flowing into the input edge port of the ATM network are reproduced at one corresponding output edge port.
An emulated circuit is carried across the ATM network on a PVC, which is configured through the network management system or the router command line interface (CLI).
The target application of the OC-3/STM-1 ATM Circuit Emulation Service network module is access to a broadband public or private ATM network where multiservice consolidation of legacy TDM, voice, video, and data traffic over a single ATM link is a requirement.
Clocking Overview
For your OC-3/STM-1 ATM Circuit Emulation Service network module to function properly, clocking must be carefully set up. Clock sources and modes must be properly configured. This overview describes the following:
Clocking Sources
Clocking at the physical interface is used to control the speed with which data is transmitted on the physical connection. This is important in delay-sensitive data types, such as voice and video, because these types of data must be received and transmitted at the same rate at every step, or hop, in a connection. To accomplish this, all the interfaces involved must be synchronized so that within a given time window the same amount of data is transmitted or forwarded at every point in the connection. If synchronization is not present, data can be lost because of buffer overflow or underflow at some point along the way. Real-time, delay-sensitive data is intolerant of such loss.
The OC-3/STM-1 ATM Circuit Emulation Service network module can use internal clock sources or it can extract clocking from an external signal. An external source is one derived from a signal coming into the ATM switch router. These can include:
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In many cases, using a clocking signal from a telephone company is the simplest and best solution for a stable and reliable clocking signal, especially in those instances where you are already connecting to telephone equipment using circuit emulation service (CES).
For example, to meet its own need for internal consistency, a telephone company typically distributes a timing signal to govern its own networking operations. Therefore, the telephone company has already addressed timing requirements similar to those that an ATM switch router user must address in relation to their own CES operations. Consequently, a private branch exchange (PBX) can serve as a ready means for providing a timing signal to any user CES device.
A primary reference source (PRS) refers to a precision reference timing signal that must be made available, wherever required, to synchronize the flow of CES data from its source to its destination. A major telephone carrier is often the source of the timing signal of choice, because such signals are known to be highly stable, reliable, and accurate. If the clock frequency is not the same at both the ingress and egress nodes of the circuit, the data queues and buffers in the network will either overflow or underflow, resulting in periodic line errors.
Clocking Types
The OC-3/STM-1 ATM Circuit Emulation Service network module is capable of using three clocking modes to meet the timing requirements of CBR data:
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Table 2 summarizes, in order of preference, the characteristics of the three clocking modes you can configure on a CES module.
Although the wander and jitter characteristics of these clocking modes differ, all clocking modes preserve the integrity of your CES data, ensuring error-free data transport from source to destination. The differences among the three modes are further described in the following sections.
Benefits
The OC-3/STM-1 ATM Circuit Emulation Service network module allows the connection of ATM networks and legacy TDM T1 and E1 lines. This functionality provides the following benefits:
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Restrictions
The OC-3/STM-1 ATM CES network module can be configured with the following restrictions:
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If you are still having trouble, enable ATM debug mode using the debug atm errors command.
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Related Documents
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Supported Platforms
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Supported Standards, MIBs, and RFCs
Standards
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MIBs
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For descriptions of supported MIBs and how to use MIBs, see the Cisco MIB web site on CCO at http://www.cisco.com/public/sw-center/netmgmt/cmtk/mibs.shtml.
RFCs
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Prerequisites
The OC-3/STM-1 ATM Circuit Emulation Service network module requires Cisco IOS Release 12.1(2)T or later.
Before you configure an interface, have the following information available:
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Timesaver
Configuration Tasks
See the following sections for configuration tasks for the OC-3/STM-1 ATM Circuit Emulation Service network module. Each task in the list indicates if the task is optional or required.
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Configuring the ATM Interface
The ATM interface on the OC-3/STM-1 ATM Circuit Emulation Service network module allows access to an ATM network, which provides the benefits of circuit switching (constant transmission delay and guaranteed capacity) with those of packet switching (flexibility and efficiency for intermittent traffic). To configure the ATM interface on the OC-3/STM-1 ATM Circuit Emulation Service network module, use the following procedures:
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This document does not explain all possible ATM interface configuration options. For complete information, see the Cisco IOS Release 12.1 Wide-Area Networking Configuration Guide and Wide-Area Networking Command Reference.
Configuring PVCs
To use a permanent virtual circuit (PVC), you must configure the PVC into both the router and the ATM switch. PVCs remain active until the circuit is removed from either configuration.To configure the ATM interface with PVCs, follow this procedure starting in global configuration mode:
Configuring SVCs
ATM switched virtual circuit (SVC) services are created and released dynamically, providing user bandwidth on demand. This service requires a signaling protocol between the router and the switch. To configure the ATM interface with SVCs, follow this procedure starting in global configuration mode:
Configuring Virtual Path Shaping
The OC-3/STM-1 ATM Circuit Emulation Service network module supports multiplexing of one or more PVCs over a virtual path (VP) that is shaped at a constant bandwidth. To use this feature, you configure a permanent virtual path (PVP) with a specific virtual path identifier (VPI). Any PVCs that are created subsequently with the same VPI are multiplexed onto this VP; the traffic parameters of individual PVCs are ignored.
The traffic shaping conforms to the peak rate that is specified when you create the VP. Any number of data PVCs can be multiplexed onto a VP.
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To create a PVP, use the following commands beginning in global configuration mode:
Step 1
Select the ATM interface to configure by entering the interface command, followed by the interface type and slot and unit number
Step 2
Create a PVP and optionally specify the peak rate.
Step 3
Optionally, create a PVC with a VPI that matches the VPI specified in Step 2.
Step 4
Router(config-if)# exitExit interface configuration mode.
Configuring the T1/E1 Controller
The T1/E1 controller on the OC-3/STM-1 ATM Circuit Emulation Service network module provides T1 or E1 connectivity to PBXs or to a central office (CO). To configure the T1 or E1 controller on the OC-3/STM-1 ATM Circuit Emulation Service network module, use the following procedures:
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For more information about configuring the T1/E1 interface on the OC-3/STM-1 ATM Circuit Emulation Service network module, see the Configuring 1- and 2-Port T1/E1 Multiflex Voice/WAN Interface Cards on Cisco 2600 and 3600 Series Routers Cisco IOS Release 12.0(5)XK online document.
Configuring the CES Clock
The OC-3/STM-1 ATM Circuit Emulation Service network module uses the CES clock and passes the clocking information to the T1 controller and ATM interface. The clock must be set up on the CES interface, and then the T1 controller and ATM interface must be configured to use either its own physical loop or the clocking information that is passed. Some examples of the CES clock settings are shown at the end of this section. To configure the CES clock, follow this procedure starting in global configuration mode:
Examples of CES Clock Configuration
Table 3shows allowable combinations for CES clocking configuration.
The following sample configurations can be used for CES clock settings.
Network Module Slave to T1 Clock
In this example the OC-3/STM-1 ATM CES network is using the T1 clock.
ces 1/0clock-select 1 T1 1/0controller T1 1/0clock source internalinterface ATM 1/0atm clock internalNetwork Module is Master Clock
In this example the OC-3/STM-1 ATM CES network module is providing the clock.
ces 1/0clock-select 1 Local Oscillatorcontroller T1 1/0clock source internalinterface ATM 1/0atm clock internalNetwork Module Slave to ATM Clock
In this example the OC-3/STM-1 ATM CES network module is using the ATM clock.
ces 1/0clock-select 1 ATM 1/0controller T1 1/0clock source internalinterface ATM 1/0no atm clock internalConfiguring Unstructured Circuit Emulation Service
This circuit consumes the entire bandwidth of the port, which is provisioned manually at the time you set up the unstructured circuit and remains dedicated to that port, whether that port is actively transmitting data or not.
A CES module converts non-ATM telephony traffic into ATM cells for propagation through an ATM network. The ATM cell stream is directed to an outgoing ATM port or non-ATM telephony port.
To configure the T1/E1 port for unstructured CES, follow this procedure starting in global configuration mode:
Configuring Structured Circuit Emulation Service
Structured CES differs from unstructured CES services in that the structured services allow you to allocate the bandwidth in a highly flexible and efficient manner. With the structured services, you use only the bandwidth actually required to support the active structured circuit(s) that you configure.
To configure the T1/E1 port for structured CES, follow this procedure starting in global configuration mode:
Configuring Channel Associated Signaling for Structured CES
Because the CES deck emulates constant bit rate services over ATM networks, it is capable of providing support for handling channel-associated signaling (CAS) information introduced into structured CES circuits by PBXs and time-division multiplexing (TDM) devices.
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The signaling supported depends on the WAN/voice interface card that is inserted in the CES deck. The signaling method depends on the connection that you are making:
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To configure the T1/E1 port for channel associated signaling, first perform the tasks in the "Configuring Structured Circuit Emulation Service" section and then perform the following tasks beginning in global configuration mode:
Configuring Echo Cancellation
Echo cancellation adds to the quality of voice transmissions by adjusting the echo that occurs on the interface because of impedance mismatches. Some echo is reassuring; echo over 25 milliseconds can cause problems. To configure the T1/E1 port for echo cancellation, perform the following tasks beginning in global configuration mode:
Activating the Connection
Once the ATM interface and T1 or E1 controllers are configured, activate the connection by performing the following task beginning in global configuration mode:
Monitoring and Maintaining the OC-3/STM-1 ATM Circuit Emulation Service Network Module
To get detailed information about the OC-3/STM-1 ATM Circuit Emulation Service network module configuration, use the following show commands:
add show atm vc
show controller type port slot
Configuration Examples
This section contains the following examples:
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PVC-to-TDM CES Connection Example
In the following example, the ATM interface clock is being used. The PVC is used by AAL1 CES and is connected to a TDM group to form a CES connection. The CES connection is between ATM interface 1/0 and T1 controller 1/0 using CES PVC 1/101 and TDM group 0. TDM Group 0 has four timeslots.
version 12.1service timestamps debug uptimeservice timestamps log uptimeno service password-encryption!hostname vpd2005!logging buffered 4096 debuggingno logging console!!ces 1/0clock-select 1 em1/0! this is the default!ip subnet-zeroip host lab 172.18.207.11ip host rtplab 172.18.207.11ip host rtpss20 172.18.207.11ip host dev 172.18.207.10ip host rtpdev 172.18.207.10!isdn voice-call-failure 0cns event-service server!!controller T1 1/0clock source internaltdm-group 0 timeslots 4-8!controller T1 1/1clock source internaltdm-group 1 timeslots 1!!interface Ethernet0/0ip address 172.18.193.220 255.255.255.0no ip directed-broadcast!interface Ethernet0/1no ip addressno ip directed-broadcast!interface Ethernet0/2no ip addressno ip directed-broadcast!interface Ethernet0/3no ip addressno ip directed-broadcast!interface ATM1/0ip address 7.7.7.7 255.255.255.0no ip directed-broadcastno atm ilmi-keepalivepvc 1/101 cespvc 1/200protocol ip 7.7.7.8 broadcast!ip classlessip route 0.0.0.0 0.0.0.0 Ethernet0/0ip route 0.0.0.0 0.0.0.0 172.18.193.1ip route 12.0.0.0 255.0.0.0 1.1.1.1no ip http server!connect test ATM1/0 1/101 T1 1/0 0!!line con 0exec-timeout 0 0transport input noneline aux 0line vty 0 4password lablogin!endVideo Traffic Configuration Example
In the following example, theOC-3/STM-1 ATM Circuit Emulation Service network module is configured for video traffic.
version 12.1service timestamps debug uptimeservice timestamps log uptimeno service password-encryption!hostname 3640!ces 1/0clock-select 1 ATM1/0!ip subnet-zerono ip routing!cns event-service server!!!controller T1 1/0framing esfclock source internallinecode b8zscablelength short 133tdm-group 0 timeslots 1-6!controller T1 1/1!interface Ethernet0/0ip address 1.2.60.127 255.255.0.0ip broadcast-address 1.2.255.255no ip route-cacheno ip mroute-cache!interface ATM1/0no ip addressno ip route-cacheno ip mroute-cacheno atm ilmi-keepalivepvc 0 0/41 ces!ip default-gateway 1.2.0.1ip classlessip route 223.255.254.0 255.255.255.0 1.2.0.1no ip http server!connect video-1 ATM1/0 0/41 T1 1/0 0!!line con 0transport input noneline aux 0line vty 0 4login!endCommand Reference
This section documents new or modified commands. All other commands used with this feature are documented in the Cisco IOS Release 12.1 command reference publications.
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ces
To configure Circuit Emulation Service (CES) on a router port and enter controller configuration mode, use the ces global configuration command.
ces slot/port
Syntax Description
slot/port
Backplane slot number and port number on the interface. The port value is always 0 as the interface configuration applies to all ports in the slot.
Defaults
No ces interface is configured.
Command Modes
Global configuration
Command History
Usage Guidelines
This command is used on Cisco 3600 series routers that have OC-3/STM-1 ATM CES network modules.
Examples
The following example configures the CES interface in slot 2:
ces 2/0Related Commands
ces-cdv
To set the cell delay variation, use the ces-cdv interface configuration command.
ces-cdv time
Syntax Description
Defaults
The default time parameter is 5000.
Command Modes
Interface-ATM-VC
Command History
Usage Guidelines
This command is used on Cisco 3600 series routers that have OC-3/STM-1 ATM CES network modules.
Examples
The following example configures the maximum tolerable cell arrival jitter at 7500 microseconds:
ces-cdv 7500Related Commands
ces-clock
To configure the clock for the CES interface, use the ces-clock controller configuration command.
ces-clock [adaptive|srts|synchronous]
Syntax Description
Defaults
The default setting is synchronous.
Command Modes
Controller configuration
Command History
Usage Guidelines
This command is used on Cisco 3600 series routers that have OC-3/STM-1 ATM CES network modules.
Examples
The following example configures the CES clock mode for synchronous residual time stamp:
ces-clock srtsRelated Commands
clock-select
To establish the sources and priorities of the requisite clocking signals for the OC-3/STM-1 ATM Circuit Emulation Service network module, use the clock-select CES configuration command.
clock-select priority-no interface slot/port
Syntax Description
Defaults
No default behavior or values.
Command Modes
CES configuration
Command History
Usage Guidelines
This command is used on Cisco 3600 series routers that have OC-3/STM-1 ATM CES network modules.
To support synchronous or synchronous residual time stamp (SRTS) clocking modes, you must specify a primary reference source to synchronize the flow of CBR data from its source to its destination.
You can specify up to four clock priorities. The highest priority active interface in the router supplies primary reference source to all other interfaces that require network clock synchronization services. The fifth priority is the local oscillator on the network module.
Use the show ces slot/port clock-select command to display the currently configured clock priorities on the router.
Examples
The following example defines two clock priorities on the router:
clock-select 1 cbr 2/0clock-select 2 atm 2/0Related Commands
connect
To define connections between T1 or E1 controller ports and the ATM interface, enter the connect global configuration command.This command is used after all interfaces are configured.
connect connection-name atm slot/port-1 [name of PVC/SVC|vpi/vci] {T1 | E1} slot/port-2 TDM-group-number
Syntax Description
Defaults
No default behavior or values.
Command Modes
Global configuration
Command History
Usage Guidelines
This command is used on Cisco 3600 series routers to provide connections between T1/E1 interfaces, between T1/E1 and ATM interfaces, and for drop-and-insert capabilities.
Examples
The following example shows how the ATM PVC and T1 TDM group are set up and then connected:
Router(config)# interface atm 1/0Router(config-if)pvc pvc1 0/100 cesRouter(config-if)exitRouter(config)# controller T1 1/1Router(config-controller)tdm-group 3 timeslots 13-24 type e&mRouter(config-controller)exitRouter(config)connect tdm1 atm 1/0 pvc1 0/100 T1 1/1 3Related Commands
echo-cancel comfort-noise
To specify that background noise should be generated, use the echo-cancel comfort-noise controller configuration command. Use the no form of this command to disable this feature.
echo-cancel comfort-noise
no echo-cancel comfort-noise
Syntax Description
This command has no arguments or keywords.
Defaults
No default behavior or values.
Command Modes
Controller configuration
Command History
Usage Guidelines
Use the echo-cancel comfort-noise command to generate background noise to fill silent gaps during calls if VAD is activated. If comfort noise is not enabled and VAD is enabled at the remote end of the connection, the user hears nothing or silence when the remote party is not speaking.
The configuration of comfort noise only affects the silence generated at the local interface; it does not affect the use of VAD on either end of the connection or the silence generated at the remote end of the connection.
For the OC-3/STM-1 ATM Circuit Emulation Service network module, echo cancellation must be enabled.
Examples
The following example enables comfort noise on a T1 controller:
controller T10/0echo-cancel enableecho-cancel comfort-noiseRelated Commands
voice port
Specifies which port is used for voice traffic.
Enables echo cancellation on a voice port.
echo-cancel compensation
To set attenuation for loud signals, use the echo-cancel compensation controller configuration command. Use the no form of this command to disable this feature.
echo-cancel compensation
no echo-cancel compensation
Syntax Description
This command has no arguments or keywords.
Defaults
No default behavior or values.
Command Modes
Controller configuration.
Command History
Usage Guidelines
Use the echo-cancel compensation command to add attenuation control to the T1 or E1 controller. When this command is enabled, -6 dB is inserted if the signal level from the receive direction is loud. When loud signals are not received, the attenuation is removed.
For the OC-3/STM-1 ATM Circuit Emulation Service network module, echo cancellation must be enabled.
Examples
The following example enables comfort noise on a T1 controller:
controller T1 0/0echo-cancel enableecho-cancel compensationRelated Commands
voice port
Specifies which port is used for voice traffic
Enables echo cancellation on a voice port.
echo-cancel coverage
To adjust the size of the maximum echo delay compensation, use the echo-cancel coverage controller configuration command. Use the no form of this command to reset this command to the default value.
echo-cancel coverage time
no echo-cancel coverage time
Syntax Description
time
Number of milliseconds (ms) the echo-canceller covers on a given signal. Valid values are 24, 32, 48, 64, 80, 96, 112, and 128 ms.
Defaults
64 ms
Command Modes
Controller configuration.
Command History
12.1(2)T
This command is supported on the OC-3/STM-1 ATM Circuit Emulation Service network module on the Cisco 3600 series routers.
Usage Guidelines
Use the echo-cancel coverage command to adjust the size of the maximum echo delay compensation. This command enables cancellation of voice that is sent out of the interface and received back on the same interface within the configured amount of time. If the local loop (the distance from the analog interface to the connected equipment producing the echo) is longer, the configured value of this command should be extended.
If you configure a longer value for this command, the echo canceller takes longer to converge; in this case, the user might hear a slight echo when the connection is initially set up. If the configured value for this command is too short, the user might hear some echo for the duration of the call because the echo canceller is not cancelling the longer delay echoes.
There is no echo or echo cancellation on the IP side of the connection.
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Examples
The following example adjusts the size of the echo canceller to 32 ms:
controller T1 0/0echo-cancel enableecho-cancel coverage 32Related Commands
echo-cancel enable
To enable the echo cancel feature, use the echo-cancel enable controller configuration command. Use the no form of this command to disable this feature..
echo-cancel enable
no echo-cancel enable
Syntax Description
This command has no arguments or keywords.
Defaults
Enabled for all interface types.
Command Modes
Controller configuration
Command History
12.1(2)T
This command is supported on the OC-3/STM-1 ATM Circuit Emulation Service network module on the Cisco 3600 series routers.
Usage Guidelines
The echo-cancel enable command enables cancellation of voice that is sent out of the interface and is received back on the same interface. Disabling echo cancellation might cause the remote side of a connection to hear an echo. Because echo cancellation is an invasive process that can minimally degrade voice quality, this command should be disabled if it is not needed.
The echo-cancel command does not affect the echo heard by the user on the analog side of the connection.
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Examples
The following example enables the echo cancel featureon a T1 controller:
controller T1 0/0echo-cancel enableecho-cancel coverage 32Related Commands
Specifies the amount of coverage for echo cancellation
voice port
Configures the voice port
echo-cancel loopback
To place the echo cancellation processor in loopback mode, use the echo-cancel loopback controller configuration command. To disable, use the no form of this command.
echo-cancel loopback
no echo-cancel loopback
Syntax Description
This command has no arguments or keywords.
Defaults
No default behavior or values.
Command Modes
Controller configuration
Command History
Usage Guidelines
You can use an echo-cancel loopback test on lines to detect and distinguish equipment malfunctions caused either by line or by the interface. If correct echo cancellation is not possible when an interface is in loopback mode, the interface is the source of the problem.
Examples
On a Cisco 3600 series router, the following example sets up echo cancellation loopback diagnostics:
controller T1 0/0echo-cancel enableecho-cancel coverage 32echo-cancel loopbackRelated Commands
pvc
To create or assign a name to an ATM permanent virtual circuit (PVC), specify the encapsulation type on an ATM PVC, or enter interface-ATM-VC configuration mode, use the pvc command in interface or subinterface configuration mode. To remove an ATM PVC, use the no form of this command.
pvc [name] vpi/vci [ilmi | qsaal | smds | ces]
no pvc [name] vpi/vci [ilmi | qsaal | smds | ces]
Syntax Description
Defaults
No PVC is defined. When a PVC is defined, the global default of the encapsulation command applies (aal-encap = aal5snap).
Command Modes
Interface or subinterface configuration
Command History
11.3 T
This command was introduced.
12.1(2)T
This command is supported on the OC-3/STM-1 ATM Circuit Emulation Service network module on the Cisco 3600 series routers.
Usage Guidelines
Creating and Configuring PVCs
The pvc command replaces the atm pvc command, which, although still supported and available, will become obsolete in the near future. Use the pvc command to configure a single ATM VC only, not a VC that is a bundle member. We recommend that you use the pvc command in conjunction with the encapsulation and random-detect attach commands instead of the atm pvc command.
The pvc command creates a PVC and attaches it to the VPI and VCI specified. Both the vpi and vci arguments cannot be simultaneously specified as 0; if one is 0, the other cannot be 0.
When configuring an SVC, use the pvc command to configure the PVC that handles SVC call setup and termination. In this case, specify the qsaal keyword. See the second example that follows.
ATM PVC Names
Once you specify a name for a PVC, you can reenter interface-ATM-VC configuration mode by simply entering the pvc name command. You can remove a PVC and any associated parameters by entering no pvc name or no pvc vpi/vci.
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Encapsulation Types on ATM PVCs
Specify ILMI, QSAAL, SMDS, or CES as the encapsulation type on an ATM PVC. (To configure other encapsulations types, see the encapsulation command.)
Rate Queues
The Cisco IOS software dynamically creates rate queues as necessary to satisfy the requests of the pvc commands.
Default Configurations
If ilmi, qsaal, smds, or ces encapsulation is not explicitly configured on the ATM PVC, the PVC inherits the following default configuration (listed in order of next highest precedence):
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Examples
The following example creates a PVC with VPI 0 and VCI 16, and communication is set up with the ILMI:
pvc cisco 0/16 ilmiexitThe following example creates a PVC used for ATM signalling for an SVC. It specifies VPI 0 and VCI 5:
pvc cisco 0/5 qsaalexit
The following example configures the PVC called cisco to use class-based weighted fair queueing (CBWFQ). It attaches a policy map called policy1 to the PVC. The classes comprising policy1 determine the service policy for the PVC:pvc cisco 0/5 service-policy output policy1vbr-nrt 2000 2000 encap aal5snapRelated Commands
show ces clock-select
To display the setting of the network clock for the specified port, use the show ces clock-select privileged EXEC command.
show ces slot/port clock-select
Syntax Description
Command Modes
Privileged EXEC
Command History
Examples
The following is sample output from the show ces clock-select command for slot 1, port 0:
router# show ces 1/0 clock-selectPriority 1 clock source:not configuredPriority 2 clock source:not configuredPriority 3 clock source:ATM1/0 UPPriority 4 clock source:Local oscillatorCurrent clock source:ATM1/0, priority:3Related Commands
Establishes the sources and priorities of the requisite clocking signals for the OC-3/STM-1 ATM Circuit Emulation Service network module.
svc
To create an ATM switched virtual circuit (SVC) on a main interface or subinterface, use the svc interface configuration command. To disable the SVC, use the no form of this command.
svc [name] {nsap address | ces}
no svc [name] {nsap address | ces}
Syntax Description
Defaults
No NSAP address is defined.
Command Modes
Interface configuration
Command History
11.3
This command was introduced.
12.1(2)T
This command is supported on the OC-3/STM-1 ATM Circuit Emulation Service network module on the Cisco 3600 series routers.
Usage Guidelines
Once you specify a name for an SVC, you can reenter the interface-ATM-VC configuration mode by simply entering svc name. You can remove an NSAP address any associated parameters by entering no svc name or no svc nsap address.
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Examples
The following example creates an SVC with the name lion and specifies the 40-digit hexadecimal destination ATM NSAP address:
svc lion nsap 47.0091.81.000000.0040.0B0A.2501.ABC1.3333.3333.05tdm-group
To configure a list of time slots for creating clear channel groups (pass-through) for Time Division Multiplexing (TDM) cross-connect, use the tdm-group controller configuration command. Use the no form of this command to delete a clear channel group.
tdm-group tdm-group-no timeslot timeslot-list [[type {e&m | fxs [loop-start | ground-start] | fxo [loop-start | ground-start] | r2-digital| r2-analog | r2-pulse}] | unstructured]
no tdm-group tdm-group-no
Syntax Description
Defaults
No TDM group is configured.
Command Modes
Controller configuration
Command History
11.3 MA
This command was introduced.
12.1(2)T
This command was modified for the OC-3/STM-1 ATM Circuit Emulation Service network module on the Cisco 3600 series routers.
Usage Guidelines
This command applies to Voice over Frame Relay, Voice over ATM, and Voice over HDLC on the Cisco MC3810 and Cisco 3600 series routers.
Note
Examples
The following example configures TDM group number 20 on controller T1 1 to support FXO ground-start:
controller T1 1tdm-group 20 timeslot 20 type fxs ground-startGlossary
ABR—Available Bit Rate service, provides a feedback path in VCs using RM cells to indicate buffer congestion and automatically decrease/increase data rate on a VC.
ATM —Asynchronous Transfer Mode (NOT Automatic Teller Machine)
CES—Circuit Emulation Service
CBR—Constant Bit Rate interfaces usually run at T1 or E1 speed and are used mostly to connect PBXs or video equipment
OC3—optical carrier level 3, the optical interface designed with synchronous transport signal (STS-3) rate in SONET.
PRS—primary reference source
PVC—permanent virtual circuit made between two data terminal equipment (DTE) lines established by configuration.
SAR—Segmentation and Reassembly, a circuit device that converts packets into cells and visa-versa.
SVC—switched virtual circuit established across a network on as-need basis.
SONET—synchronous optical network
STM-1—Synchronous Transfer Mode level 1
UBR—Unspecified Bit Rate service category for ATM traffic. This is intended for non-real time burst applications which do not require a guarantee of traffic characteristics such as bandwidth, cell delay and cell delay
VBR—variationvariable bit rate
VC—Virtual Circuit
VCI—Virtual Channel Identifier
VPI—Virtual Path Identifier
rt-VBR—Real time Variable Bit Rate traffic service category for ATM traffic.
nrt-VBR—Non-real time Variable Bit Rate traffic service category for ATM traffic.
