- Cisco IOS Wide-Area Networking Command Reference, Release 12.2
Table Of Contents
ima differential-delay-maximum
atm txbuff
To set the maximum number of transmit buffers for simultaneous packet fragmentation, use the atm txbuff interface configuration command. To restore the default value, use the no form of this command.
atm txbuff number
no atm txbuff
Syntax Description
number
Maximum number of packet fragmentations that the ATM Interface Processor (AIP) can perform simultaneously, from 0 to 512.
Defaults
256
Command Modes
Interface configuration
Command History
Usage Guidelines
This command is supported on the AIP for Cisco 7500 series routers. This command is not supported on the ATM port adapter for Cisco 7200 and 7500 series routers, nor is it supported on Cisco 4500 and Cisco 4700 routers.
Examples
The following example configures the AIP to perform up to 300 packet fragmentations simultaneously:
atm txbuff 300atm uni-version
To specify the User-Network Interface (UNI) version (3.0 or 3.1) the router should use when Interim Local Management Interface (ILMI) link autodetermination is unsuccessful or ILMI is disabled, use the atm uni-version interface configuration command. To restore the default value to 3.0, use the no form of this command.
atm uni-version version-number
no atm uni-version version-number
Syntax Description
Defaults
Version 3.0
Command Modes
Interface configuration
Command History
Usage Guidelines
Normally, when the ILMI link autodetermination is enabled on the interface and is successful, the router accepts the UNI version returned by ILMI. If the ILMI link autodetermination is unsuccessful or ILMI is disabled, the UNI version defaults to 3.0. You can override the default UNI version by using this command to enable UNI 3.1 signalling support. The no form of the command sets the UNI version to one returned by ILMI if ILMI is enabled and the link autodetermination process is successful. Otherwise, the UNI version reverts to 3.0.
Examples
The following example specifies UNI version 3.1 signalling port on the ATM interface 2/0:
interface atm 2/0atm uni-version 3.1atm vc-per-vp
To set the maximum number of virtual channel identifier (VCIs) to support per virtual path identifier (VPI), use the atm vc-per-vp interface configuration command. To restore the default value, use the no form of this command.
atm vc-per-vp number
no atm vc-per-vp
Syntax Description
Defaults
1024
Command History
Usage Guidelines
This command controls the memory allocation in the ATM Interface Processor (AIP), ATM port adapter, ATM network module, or network processor module (NPM) to deal with the VCI table.
An invalid VCI causes a warning message to be displayed.
Cisco 2600 and 3600 series with IMA
Note
For Cisco 2600 and 3600 series with IMA, changing the value of the atm vc-per-vp command on one interface affects all of the interfaces on that network module.
Table 3 lists the possible VCI ranges and corresponding VPI ranges for the Cisco 2600 and 3600 series with IMA.
Table 3 VCI and VPI Ranges for Cisco 2600 and 3600 Series with IMA
0-255
0-15, 64-79, 128-143, and 192-207
0-511
0-15, 64-79
0-1023
0-15
Examples
The following example sets the maximum number of VCIs per VPI to 512:
atm vc-per-vp 512Related Commands
atm vp-filter
To set the ATM Interface Processor (AIP) filter register, use the atm vp-filter interface configuration command. To restore the default value, use the no form of this command.
atm vp-filter hexvalue
no atm vp-filter
Syntax Description
Defaults
0x7B
Command Modes
Interface configuration
Command History
Usage Guidelines
This command is supported on Cisco 7500 series routers, but not on Cisco 4500 and Cisco 4700 routers. This command is not supported on ATM port adapters.
This command allows you to specify a virtual path identifier (VPI) or range of VPIs to be used for ATM adaptation layer 3/4 (AAL3/4) processing. All other VPIs map to AAL5 processing. If only AAL5 processing is required, you can either let the virtual path filter default or set it to an arbitrary VPI so that AAL5 processing is performed on all VPIs.
This command configures the hexadecimal value used in the virtual path filter register in the reassembly operation. The virtual path filter comprises 16 bits. The virtual path filter register uses the most significant bits (bits 15 through 8, the left half of the filter) as mask bits, and uses bits 7 through 0 (the right half of the filter) as compare bits.
When a cell is received, the right half of the filter is exclusively NORed with the binary value of the incoming VPI. The result is then ORed with the left half of the filter (the mask). If the result is all 1s, then reassembly is done using the VCI/message identifier (MID) table (AAL3/4 processing). Otherwise, reassembly is done using the VPI-VCI pair table (AAL5 processing).
Examples
In the following example, all incoming cells are reassembled using AAL3/4 processing:
atm vp-filter ff00In the following example, all incoming cells with the virtual path equal to 0 are reassembled using AAL3/4 processing; all other cells are reassembled using AAL5 processing:
atm vp-filter 0In the following example, all incoming cells with the most significant bit of the virtual path set are reassembled using AAL3/4 processing; all other cells are reassembled using AAL5 processing:
atm vp-filter 7f80broadcast
To configure broadcast packet duplication and transmission for an ATM virtual circuit (VC) class, permanent virtual circuit (PVC), switched virtual circuit (SVC), or VC bundle, use the broadcast command in the appropriate command mode. To disable transmission of broadcast packets for your ATM VC class, PVC, SVC, or VC bundle, use the no form of this command. To restore the default behavior according to the description in the following "Usage Guidelines" section, use the default form of this command.
broadcast
no broadcast
default broadcast
Syntax Description
This command has no arguments or keywords.
Defaults
Disabled. For classical IP SVCs, broadcast is enabled.
Command Modes
Interface-ATM-VC configuration (for ATM PVCs and SVCs)
VC-class configuration (for a VC-class)
Bundle configuration (for a VC bundle)
PVC range configuration (for an ATM PVC range)
PVC-in-range configuration (for an individual PVC within a PVC range)
Command History
Usage Guidelines
If broadcasting and multipoint signalling are enabled on an SVC, a multipoint SVC will be created to handle the SVC.
Note
If the broadcast command is not explicitly configured on an ATM PVC, SVC, or VC bundle, the VC inherits the following default configuration (listed in order of precedence):
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Note
To use the broadcast command in bundle configuration mode, enter the bundle command to enact bundle configuration mode for the bundle for which you want to enable broadcast forwarding.
Examples
The following example enables the transmission of broadcast packets on an ATM PVC named router5:
pvc router5 1/32 broadcastThe following example enables the transmission of broadcast packets on an ATM PVC bundle named chicago:
bundle chicago broadcastRelated Commands
cbr
To configure the constant bit rate (CBR) for the ATM circuit emulation service (CES) for an ATM permanent virtual circuit (PVC) on the Cisco MC3810, use the cbr command in the appropriate configuration mode. To restore the default, use the no form of this command.
cbr rate
no cbr rate
Syntax Description
rate
Constant bit bate (also known as the average cell rate) for ATM CES. The valid range for this command is from 56 to 10,000 kbps on the Cisco MC3810.
Defaults
The CBR is not configured.
Command Modes
Interface-ATM-VC configuration (for ATM PVCs and SVCs)
PVC range configuration (for an ATM PVC range)
PVC-in-range configuration (for an individual PVC within a PVC range)
Command History
12.0
This command was introduced.
12.1(5)T
This command was made available in PVC range and PVC-in-range configuration modes.
Usage Guidelines
This command applies to ATM configuration on the Cisco MC3810.
Examples
The following example configures the constant bit rate on ATM PVC 20 on the Cisco MC3810:
pvc 20cbr 56Related Commands
ces
To configure Circuit Emulation Service (CES) on a router port and enter CES 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 2600 series and 3600 series routers that have OC-3/STM-1 ATM CES network modules.
The ces command enters CES configuration mode. Use CES configuration mode to configure CES parameters such as the CES clock.
Examples
The following example configures the CES interface in slot 2:
ces 2/0Related Commands
ces aal1 clock
To configure the ATM adaptation layer 1 (AAL1) timing recovery clock for the constant bit rate (CBR) interface, use the ces aal1 clock interface configuration command. To return the clock to the default, use the no form of this command.
ces aal1 clock {adaptive | srts | synchronous}
no ces aal1 clock
Syntax Description
Defaults
synchronous
Command Modes
Interface configuration
Command History
Usage Guidelines
The clock mode must be synchronous for structured mode. In unstructured mode, use the adaptive keyword when a network-derived clock is not available.
Use the srts keyword when a network-derived clock is available but devices attached to the CES port use a different clock reference. The srts keyword samples the incoming clock, subtracts from the network clock, and sends the remainder in an AAL1 header. The clock is reconstructed during output by adding the residual to the network reference.
Use the synchronous keyword for all other modes.
Examples
The following command sets the AAL1 timing recovery clock to adaptive mode:
interface cbr 4/0ces aal1 clock adaptiveRelated Commands
ces aal1 service
To configure the type of circuit emulation service used on the constant bit rate (CBR) interface, use the ces aal1 service interface configuration command. To return the type of service to unstructured, use the no form of this command.
ces aal1 service {structured | unstructured}
no ces aal1 service
Syntax Description
structured
Sets the type of service to structured (cross-connect).
unstructured
Sets the type of service to unstructured (clear-channel).
Defaults
unstructured
Command Modes
Interface configuration
Command History
Usage Guidelines
The structured keyword means that each time slot is an independent entity grouped into circuits, where each circuit has an independent permanent virtual circuit (PVC).
The unstructured keyword reduces the incoming serial data on the receiving end of the ATM network. The keyword also sets the service to single circuit, single PVC, where all time slots are carried.
Examples
The following example changes the mode for the ces aal1 service command to structured:
interface cbr 4/0ces aal1 service structuredRelated Commands
ces-cdv
To set the cell delay variation, use the ces-cdv interface-ATM-VC configuration command.
ces-cdv time
Syntax Description
Defaults
5000 microseconds
Command Modes
Interface-ATM-VC configuration
Command History
Usage Guidelines
This command is used on Cisco 2600 series and 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:
interface atm1/0pvc 0 0/41 cesces-cdv 7500Related Commands
ces circuit
To configure the connection attributes for the constant bit rate (CBR) interface, use the ces circuit interface configuration command. To return the connection attributes to the default or to enable the circuit, use the no form of this command.
ces circuit circuit-number [cas] [cdv range] [circuit-name name] [on-hook-detection hex-number] [partial-fill range] [shutdown] [timeslots range]
no ces circuit circuit-number [cas] [cdv range] [circuit-name name] [on-hook-detection hex-number] [partial-fill range] [shutdown] [timeslots range]
Syntax Description
Defaults
No circuit is configured.
Command Modes
Interface configuration
Command History
Usage Guidelines
Channel-associated signalling (CAS) provides information about the time slot (on or off the hook) and is updated once per multiframe.
With both the CAS and on-hook detection features enabled, these features work together to enable an ingress node in an ATM network to monitor on-hook and off-hook conditions for a specified 1 x 64 structured CES circuit. As implied by the notation "1 x 64," the on-hook detection (or bandwidth-release) feature is supported only in a structured CES circuit that involves a single time slot at each end of the connection.
The time slot configured for the structured CES circuit at the ingress node (time slot 2) can be different from the DS0 time slot configured at the egress node (time slot 4). Only one such time slot can be configured at each end of the circuit when the on-hook detection feature is used.
When you invoke the on-hook feature, the ingress ATM-CES port adapter monitors the ABCD bits in the incoming CBR bit stream to detect on-hook and off-hook conditions in the circuit. In an "off-hook" condition, all the bandwidth provisioned for the specified CES circuit is used for transporting ATM AAL1 cells across the network from the ingress node to the egress node.
In an on-hook condition, the network periodically sends dummy ATM cells from the ingress node to the egress node to maintain the connection. However, these dummy cells consume only a fraction of the circuit's reserved bandwidth, leaving the rest of the bandwidth available for use by other network traffic. This bandwidth-release feature enables the network to make more efficient use of its resources.
When the CAS feature is enabled for a CES circuit, the bandwidth of the DS0 channel is limited to 56 kbps for user data, because CAS functions consume 8 kbps of channel bandwidth for transporting the ABCD signalling bits. These signalling bits are passed transparently from the ingress node to the egress node as part of the ATM AAL1 cell stream.
In summary, when the optional CAS and on-hook detection features are enabled, the following conditions apply:
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Examples
The following example sets the structured service CDV range to 5000 milliseconds and enables the interface:
interface cbr 4/0ces circuit 3 cdv 5000ces circuit 3 no shutdownRelated Commands
ces dsx1 clock source
To configure a transmit clock source for the constant bit rate (CBR) interface, use the ces dsx1 clock source interface configuration command. To return the clock source to the default, use the no form of this command.
ces dsx1 clock source {loop-timed | network-derived}
no ces dsx1 clock source
Syntax Description
loop-timed
Configures the transmit clock to loop (RX-clock to TX-clock).
network-derived
Configures the transmit clock to be derived from the network.
Defaults
network-derived
Command Modes
Interface configuration
Command History
Examples
The following example sets the clock source to loop-timed:
interface cbr 4/0ces dsx1 clock source loop-timedRelated Commands
ces dsx1 framing
To select the frame type for the data line on the constant bit rate (CBR) interface, use the ces dsx1 framing interface configuration command. To return the frame type to the default, use the no form of this command.
T1
ces dsx1 framing {esf | sf}
no ces dsx1 framing
E1
ces dsx1 framing {e1_crc_mfCASlt | e1_crc_mf_lt | e1_lt | e1_mfCAS_lt}
no ces dsx1 framing
Syntax Description
Defaults
esf (for T1)
e1_lt (for E1)
Command Modes
Interface configuration
Command History
Usage Guidelines
Use this command in configurations where the router communicates with the data line. The service provider determines which framing type is required for your circuit.
Examples
The following example sets the data line type to super frame:
interface cbr 4/0ces dsx1 framing sfRelated Commands
ces dsx1 lbo
To configure cable length for the constant bit rate (CBR) interface, use the ces dsx1 lbo interface configuration command. To return the cable length to the default, use the no form of this command.
ces dsx1 lbo length
no ces dsx1 lbo
Syntax Description
length
Sets the cable length. Values (in feet) are 0_110, 110_200, 220_330, 330_440, 440_550, 550_660, 660_above, and square_pulse. Values represent a range in feet.
Defaults
0_110 feet
Command Modes
Interface configuration
Command History
Usage Guidelines
Set the cable length to the desired number of feet on your system.
Examples
The following example sets the cable length to 440 feet:
interface cbr 4/0ces dsx1 lbo 440_550Related Commands
ces dsx1 linecode
To select the line code type for the constant bit rate (CBR) interface, use the ces dsx1 linecode interface configuration command. To return the line code to the default, use the no form of this command.
T1
ces dsx1 linecode {ami | b8zs}
no ces dsx1 linecode
E1
ces dsx1 linecode {ami | hdb3}
no ces dsx1 linecode
Syntax Description
Defaults
b8zs (for T1)
hdb3 (for E1)
Command Modes
Interface configuration
Command History
Usage Guidelines
Use this command in configurations where the switch communicates with the data line. The service provider determines which line code type is required for your circuit.
Examples
The following example specifies B8ZS as the line code type:
interface cbr 4/0ces dsx1 linecode b8zsRelated Commands
ces dsx1 loopback
To enable a loopback for the constant bit rate (CBR) interface, use the ces dsx1 loopback interface configuration command. To disable the loopback, use the no form of this command.
ces dsx1 loopback {line | noloop | payload}
no ces dsx1 loopback {line | noloop | payload}
Syntax Description
Defaults
No loopback
Command Modes
Interface configuration
Command History
Usage Guidelines
This command is useful for testing the circuit emulation port adapter module.
Examples
The following example sets a payload loopback:
interface cbr 4/0ces dsx1 loopback payloadRelated Commands
ces dsx1 signalmode robbedbit
To enable the signal mode as robbed bit on a constant bit rate (CBR) interface, use the ces dsx1 signalmode robbedbit interface configuration command. To return the signal mode to the default, use the no form of this command.
ces dsx1 signalmode robbedbit
no ces dsx1 signalmode robbedbit
Syntax Description
This command has no arguments or keywords.
Defaults
No signal mode is enabled.
Command Modes
Interface configuration
Command History
Usage Guidelines
A T1 frame consists of 24 time slots (DS0) that send at a rate of 64 kbps. T1 defines the ability to send signalling in-band on individual time slots by removing the low bit of each byte for signalling in robbedbit mode. This procedure allows 8 kbps for signalling and leaves 56 kbps for data.
In structured mode, you can send the T1 signalling information across the network. Structured mode means that after you enable robbedbit signalling mode on the port, and enable CAS on individual circuits that need this type of service, you are robbing bits from the DS0. The system then puts the bits in the specified format to be sent across the network and reinserts them at the passive side on the CES-IWF connection.
Examples
The following example enables channel-associated signalling and robbed bit signalling:
interface cbr 4/0ces circuit 1 casces dsx1 signalmode robbedbitRelated Commands
ces partial-fill
To configure the number of user octets per cell for the ATM circuit emulation service (CES), use the ces partial-fill command in interface configuration mode. To delete the CES partial-fill value, use the no form of this command.
ces partial-fill octets
no ces partial-fill octets
Syntax Description
Defaults
47 octets
Command Modes
Interface configuration
Command History
Usage Guidelines
This command applies to ATM configuration on the Cisco MC3810.
Setting the value of the ces partial-fill command to zero disables partial cell fill and causes all cells to be completely filled before they are sent. This command is supported on serial ports 0 and 1 when the encapsulation atm-ces command is enabled.
Examples
The following example sets the CES partial cell fill to 20 octets per cell for serial port 0:
interface serial 0ces partial-fill 20Related Commands
ces pvc
To configure the destination port for the circuit on the constant bit rate (CBR) interface, use the ces pvc interface configuration command. To remove the destination port on the circuit, use the no form of this command.
