Usage Guidelines

The list names and default that you set with the aaa authentication arap command are used with the arap authentication command. Note that ARAP guest logins are disabled by default when you enable AAA. To allow guest logins, you must use either the guest or auth-guest method listed in the table below. You can only use one of these methods; they are mutually exclusive.

Create a list by entering the aaa authentication arap list-name method command, where list-name is any character string used to name this list (such as MIS-access ). The method argument identifies the list of methods the authentication algorithm tries in the given sequence. See the table below for descriptions of method keywords.

To create a default list that is used if no list is specified in the arap authentication command, use the default keyword followed by the methods you want to be used in default situations.

The additional methods of authentication are used only if the previous method returns an error, not if it fails.

Use the more system:running-config command to view currently configured lists of authentication methods.

Note

In the table below, the group radius , group tacacs + , and group group-name methods refer to a set of previously defined RADIUS or TACACS+ servers. Use the radius-server host and tacacs+-server host commands to configure the host servers. Use the aaa group server radius and aaa group server tacacs+ commands to create a named group of servers.

Usage Guidelines

If the abr command is not explicitly configured on an ATM PVC, the VC inherits the following default configuration (listed in order of precedence):

• Configuration of any QoS command (abr ubr , ubr+ , or vbr-nrt ) in a VC class assigned to the PVC itself.

• Configuration of any QoS command (abr , ubr , ubr+ , or vbr-nrt ) in a VC class assigned to the PVC’s ATM subinterface.

• Configuration of any QoS command (abr , ubr , ubr+ , or vbr-nrt ) in a VC class assigned to the PVC’s ATM main interface.

• Global default value: ABR QoS at the maximum line rate of the PVC.

ABR is a quality of service class defined by the ATM Forum for ATM networks. ABR is used for connections that do not require timing relationships between source and destination. ABR provides no guarantees in terms of cell loss or delay, providing only best-effort service. Traffic sources adjust their transmission rate in response to information they receive describing the status of the network and its capability to successfully deliver data.

In ABR transmission, the peak cell rate (PCR) specifies the maximum value of the allowed cell rate (ACR), and minimum cell rate (MCR) specifies the minimum value for the ACR. ACR varies between the MCR and the PCR and is dynamically controlled using congestion control mechanisms.

Usage Guidelines

The atm command was introduced in Cisco IOS XE Release 3.4.0S to support clear T3 ATM on the Cisco ASR 1000 Series Routers. The Circuit Emulation SPA for which the atm command is used is SPA-2CHT3-CE-ATM. In Cisco IOS XE Release 3.5.0S, clear E3 ATM has been introduced in the SPA-2CHT3-CE-ATM .

Usage Guidelines

This command is supported on Cisco 7500 series routers with ATM Interface Processor (AIP). This command is not supported on the ATM port adapter. Because Cisco 4500 and Cisco 4700 routers always support both AAL3/4 and AAL5, this command is not required on Cisco 4500 and Cisco 4700 routers.

Only one virtual circuit can exist on a subinterface that is being used for AAL3/4 processing, and that virtual circuit must be an AAL3/4 virtual circuit.

The AAL3/4 support feature requires static mapping of all protocols except IP.

Usage Guidelines

To configure an ABR VC, use the pvc command with the abr keyword.

To verify the ABR rate factor, use the show atm interface atm EXEC command.

Usage Guidelines

This command enables a router to register its address with the ILMI for callback when specific events occur, such as incoming Simple Network Management Protocol (SNMP) traps or incoming new network prefixes.

Usage Guidelines

If an NSAP address is specified, the ARP client on this interface uses the specified host as an ARP server. You can specify multiple ATM ARP servers by repeating the command. If self is specified, this interface acts as the ARP server for the logical IP network.

The ATM ARP server takes one of the following actions if a destination listed in the server’s ARP table expires:

• If a virtual circuit still exists to that destination, the server sends an Inverse ARP request. If no response arrives, the entry times out.

• If a virtual circuit does not exist to the destination, the entry times out immediately.

This implementation follows RFC 1577 , Classical IP over ATM .

To configure redundant ARP servers, you must first enable redundant ARP server support by entering the atm classic-ip-extensions command with the BFI keyword.

Usage Guidelines

Use this command to configure retry frequency of create-on-demand PVCs, when the initial VC creation fails due to reasons such as temporary shortage of resource.

Usage Guidelines

When the atm bandwidth dynamic command is enabled, all of the permanent virtual circuits (PVCs) configured on an IMA group interface are created again if the total available IMA group bandwidth changes.

There must be at least one active link on the IMA group interface for dynamic bandwidth changes to take effect.

Automatic bandwidth management is supported only for the following quality of service (QoS) classes:

• UBR--unspecified bit rate

• ABR--available bit rate

• VBR-NRT--variable bit rate nonreal-time

If necessary and applicable for a particular PVC based on its QoS class, new values are applied for the following parameters when PVCs are re-created:

• peak cell rate (PCR)--all supported QoS classes

• minimum cell rate (MCR)--ABR QoS

• sustainable cell rate (SCR)--VBR-NRT QoS

The algorithm used to implement automatic bandwidth management is applied only when dynamic changes to an IMA group interface occur. It is not applied at virtual circuit creation on router bootup.

Note	PVCs may have incorrect QoS parameters if the atm bandwidth dynamic command is disabled after changing the total bandwidth, and enabled again after changing the total bandwidth once more.

Usage Guidelines

Cisco’s implementation of the ATM ARP server supports redundant ATM ARP servers on a single logical IP subnetwork (LIS ). In order for redundant ATM ARP server support to work, all of the devices on the LIS must be Cisco devices and must have the atm classic-ip-extensions BFI command configured.

The none keyword enables behavior that complies with RFC 1577, Classical IP over ATM . RFC 1577 does not support redundant ARP servers.

Usage Guidelines

When the ATM interface uses the transmit clock signal from the remote connection (the line), the switch provides the clocking.

This command is meaningless on a 4B/5B physical layer interface module (PLIM).

For SONET interfaces, use the atm clock internal command to configure an ATM port adapter to supply its internal clock to the line.

Usage Guidelines

This command applies to ATM configuration on the Cisco MC3810 multiservice concentrator.

Usage Guidelines

DS3 scrambling is used to assist clock recovery on the receiving end.

Usage Guidelines

You must enable the ATM interface before using the atm e164 auto-conversion command.

When an interface is configured for E.164 auto conversion, ATM E.164 format addresses are converted to the corresponding native E.164 address for outgoing calls. For incoming calls, native E.164 addresses are converted to the corresponding ATM E.164 format.

Usage Guidelines

E3 scrambling is used to assist clock recovery on the receiving end.

Usage Guidelines

ILMI permanent virtual circuit (PVC) should have been created under the ATM main interface.

The atm enable-ilmi-trap command is supported only on Cisco 12000 routers.

Usage Guidelines

You can use the MAC address of any other physical interface as the MAC address of a subinterface, in conjunction with the Dynamic Host Configuration Protocol (DHCP) client. You can also configure an explicit MAC address for an ATM point-to-point subinterface.

Usage Guidelines

The atm esi-address command allows you to configure the ATM address by entering the ESI (12 hexadecimal characters) and the selector byte (2 hexadecimal characters). The ATM prefix (26 hexadecimal characters) will be provided by the ATM switch. To get the prefix from the ATM switch, the ILMI permanent virtual circuit (PVC) must be configured on the router and the ATM switch must be able to supply a prefix via ILMI. A period must be used to separate the esi from the selector arguments.

Note	When ILMI is configured, use the atm esi-address command instead of the atm nsap-address command. The atm esi-address and atm nsap-address commands are mutually exclusive. Configuring the router with the atm esi-address command negates the atm nsap-address setting, and vice versa.

The ILMI PVC must be configured in order to get an NSAP address prefix from the switch.

Usage Guidelines

This command is supported on ATM interface processor (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.

The exception queue is used for reporting ATM events, such as cycle redundancy check (CRC) errors.

Usage Guidelines

This command is available on Cisco 4500 and 4700 routers with DS3 access speeds, Cisco 7200 series routers, and Cisco 7500 series routers.

Framing on the interface must match that on the switch for this ATM link.

Usage Guidelines

The default framing is described in the ITU-T Recommendation G.751.

Framing on the interface must match that on the switch for this ATM link.

Usage Guidelines

The atm max-channels command replaces the atm tx-channels command.

Transmit Descriptors

The atm max-channels command can be used to divide the available number (fixed) of transmit descriptors across the configured number of transmit channels. Typically, you think of a one-to-one association between a transmit channel and a VC; however, the ATM-CES port adapter supports other types of VCs than data VCs (for example CES VCs). Also, the ATM-CES port adapter can multiplex one or more VCs over a single virtual path (VP) that is shaped, and the VP only requires a single transmit channel. Therefore, the term transmit channel is used rather than virtual circuit .

Maximum Burst

The maximum burst of packets that are allowed per VC is limited by the number of transmit descriptors allocated per VC. Because the total number of transmit descriptors available is limited by the available SRAM space, configuration of the number of transmit channels for the interface determines the number of transmit descriptors for each transmit channel. Hence the burst size for each transmit channel is determined by the atm max-channels command. For example, for 64 (the default) transmit channels for the interface, 255 transmit descriptors are associated per channel, and for 512 transmit channels for the interface, 31 transmit descriptors are associated per channel.

To display information about the transmit descriptors, use the show atm interface atm command.

Usage Guidelines

This command is supported on Cisco 7500 series routers; it is not supported on the Cisco 4500 and Cisco 4700 routers, which have a fixed maximum of 1024 VCs.

This command sets the maximum value supported for the vcd argument in the atm pvc command. It also determines the maximum number of virtual circuits on which the AIP allows segmentation and reassembly (SAR) to occur. However, if you set a maxvc limit and then enter the atm pvc command with a larger value for the vcd argument, the software does not generate an error message.

This command does not affect the virtual path identifier (VPI)-virtual channel identifier (VCI) pair of each virtual circuit.

Usage Guidelines

This command is supported on Cisco 7200 and 7500 series routers.

MID numbers are used by receiving devices to reassemble cells from multiple sources into packets.

This command limits the number of discrete messages allowed on the PVC at the same time. It does not limit the number of cells associated with each message.

The maximum set by the atm mid-per-vc command overrides the range between the midhigh and midlow values set by the atm pvc command. If you set a maximum of 16 but a midlow of 0 and a midhigh of 255, only 16 MIDs (not 256) are allowed on the virtual circuit.

Usage Guidelines

This command is supported on Cisco 7500 series, Cisco 4500, and Cisco 4700 routers. This command is not supported on the ATM port adapter.

Each AAL3/4 subinterface is allowed only one multicast E.164 address. This multicast address is used for all protocol broadcast operations.

Usage Guidelines

This command applies to switched virtual circuits (SVCs) only, not to permanent virtual circuits (PVCs).

This command has no effect unless ATM multipoint signaling is enabled on the interface.

Usage Guidelines

If multipoint signaling is enabled, the router uses existing static map entries that have the broadcast keyword set to establish multipoint calls. One call is established for each logical subnet of each protocol.

All destinations are added to the call. One multicast packet is sent to the ATM switch for each multipoint call. The ATM switch replicates the packet to all destinations.

The atm multipoint-interval command determines how often new destinations can be added to a multipoint call.

Note	Prior to Cisco IOS Release 11.1, when this command was used on the main interface, it also affected all subinterfaces. For Release 11.1 and later, explicit configuration on each subinterface is required to obtain the same functionality.

Usage Guidelines

When configuring an SVC, you must use the atm nsap-address command to define the source NSAP address. It identifies a particular port on the ATM network and must be unique across the network.

Note

When the Integrated Local Management Interface (ILMI) is configured, use the atm esi-address command instead of the atm nsap-address command. The atm esi-address and atm nsap-address commands are mutually exclusive. Configuring the router with the atm esi-address command negates the atm nsap-address setting, and vice versa.

Configuring a new address on the interface overwrites the previous address. The router considers the address as a string of bytes and will not prefix or suffix the address with any other strings or digits. The complete NSAP address must be specified, because this value is used in the Calling Party Address Information Element in the SETUP message to establish a virtual circuit.

ATM NSAP addresses have a fixed length of 40 hexadecimal digits. You must configure the complete address in the following dotted format:

xx.xxxx.xx.xxxxxx.xxxx.xxxx.xxxx.xxxx.xxxx.xxxx.xx

Note	All ATM NSAP addresses should be entered in the dotted hexadecimal format shown above, which conforms to the User-Network Interface (UNI) specification.The dotted method provides some validation that the address is a legal value. If you know your address format is correct, the dots may be omitted.

Usage Guidelines

Use the show interfaces atm command to determine whether generation of OAM AIS alarms is enabled.

Usage Guidelines

This command disables bandwidth management for service categories other than CBR.

When infinite bandwidth oversubscription is enabled, the interface allows as much bandwidth as possible with no upper limits (except on digital subscriber line (DSL) ATM interfaces, in which oversubscription is a not infinite, but is a factor of 2). The system determines if the ATM link is already oversubscribed. If so, the command is rejected. Otherwise, the total bandwidth available on the link is recorded, and all future connection setup requests are monitored to ensure that the link is not oversubscribed.

The bandwidth allocated for each service category appears in the output of the show atm interface atm command.

The ATM bandwidth manager tracks the bandwidth used by virtual circuits (VCs) on a per-interface basis. Because many services require guaranteed bandwidth (for example, for variable bit rate-real time (VBR-RT), available bit rate (ABR), and CBR), bandwidth management is required. The purpose of the bandwidth manager is to reserve resources for connections that require guaranteed services. Bandwidth management for CBR is turned on automatically for all interfaces supporting CBR. Bandwidth management for other service categories must be turned on by the user. All service categories outside CBR are monitored only if specifically requested.

Note	Because unspecified bit rate (UBR) does not provide guaranteed bandwidth, the bandwidth specified for a UBR connection is not used in any calculations.

Bandwidth checking for a permanent virtual circuit (PVC) is done when that PVC is configured. Bandwidth checking for a switched virtual circuit (SVC) is done when a signaling call is placed or received.

When you use the atm pvp command, the system checks if the specified bandwidth is available on the interface. If the bandwidth available is greater than or equal to the peak rate specified for the Permanent Virtual Path (PVP), the command is accepted; otherwise, the command is rejected.

Within the VC mode, the available bandwidth check will determine whether the bandwidth is already used by the VC to fulfill the request. If the VC being configured is a PVC and belongs to a PVP, the bandwidth available on the PVP is used for the check; otherwise, the bandwidth available on the interface is used for the check.

When services within a VC class are being configured, the check determines whether the new bandwidth requirement can be fulfilled for all VCs using the class (on a per-interface basis) by comparing it with the bandwidth available on the corresponding interface.

Bandwidth checking for an SVC occurs before a SETUP message is sent for an outbound call. If the bandwidth check fails, the SETUP message is not sent. If the bandwidth check passes, the traffic class from which the service category is inherited is updated with the requirements for the new SVC.

When an SVC setup is requested for remotely initiated calls, a bandwidth check occurs as soon as the SETUP message is received. This bandwidth check has two components:

• Match the bandwidth requested by the remote end with the bandwidth configured locally.

• Check if bandwidth configured locally can be satisfied currently.

If the bandwidth check fails, a RELEASE message is sent out, and the call is rejected. If the bandwidth check passes, resources are reserved for the VC, and the call is accepted.

Cisco 10000 Series Router

Oversubscription of the ATM interfaces is off by default. Oversubscription of the tunnels (the number and bandwidth of VCs that can be in a tunnel) is on by default and is not subject to any oversubscription factor. Oversubscription of the tunnels cannot be adjusted or turned off. On the Cisco 10000 Series router, to enable the oversubscription feature for a particular interface or tunnel, use the atm over-subscription-factor command (but not the atm oversubscribe command, which can cause undesirable results). To prevent oversubscription of the interface, use the no atm oversubscribe command.

With variable bit rate-nonreal time (VBR-NRT) oversubscription, because of congestion on the physical interface, the accuracy of priority queueing (PQ) and class-based weighted fair queueing (CBWFQ) on individual VCs degrades. For example, if you configure each of three queues at a distribution of 50, 30, and 20 percent, respectively, the actual distribution might be 45, 40, and 15 percent, respectively. The distribution of bandwidth for each VC might be less than expected based on the speed of the VC. Typically, low-speed VCs are allocated the expected bandwidth, and high-speed VCs share the remaining bandwidth equally. The amount of bandwidth allocated for the PQ or latency might be less than expected.

Usage Guidelines

Resource limitations on Cisco xDSL interfaces require a way to configure bandwidth oversubscription up to a defined bandwidth (a finite oversubscription of bandwidth). For this requirement, the atm oversubscribe factor command is used. A DSL ATM interface supports only an oversubscribe factor of 2.

Oversubscription is allowed on variable bit rate real time class (VBR-rt), variable bit rate non-real time class (VBR-nrt), and unspecified bit rate plus (UBR+) permanent virtual circuits (PVCs). With oversubscription enabled, multiple VBR-rt, VBR-nrt, and UBR+ PVCs can be configured even when the sum of their sustainable cell rates (SCRs) exceeds the actual bandwidth available over the physical line. For example, if oversubscription is enabled and an oversubscription factor of 2 is set for a line rate of 2304 kbps, the sum of SCRs and minimum desired cell rates of VBR-rt, VBR-nrt, and UBR+ PVCs must be less than or equal to 4608 kbps, excluding the constant bit rate (CBR) PVC bandwidth.

An oversubscription factor of 2 is used internally; that is, VBR and UBR+ PVCs with a sum of SCRs up to twice the current line rate are valid. If you configure VBR-rt, VBR-nrt, or UBR+ for more than the configured oversubscription factor, the PVCs will be configured when bandwidth is available. But when no oversubscription bandwidth is available, a PVC is downgraded to an unspecified bit rate (UBR) (CBR PVCs are not affected, however); in this state, if you try to configure VBR or UBR+ PVCs beyond the line rate, the new PVCs will be downgraded to UBR state. If you have no oversubscription configured, each virtual circuit (VC) receives up to its configured SCR value of traffic, and VCs with higher SCR values receive more bandwidth. For example, if VC1 is a VBR-rt PVC configured with peak cell rate (PCR) and SCR line rates of 2304 kbps (command vbr-rt 2304 2304 ), VC2 is a VBR-nrt PVC configured with PCR and SCR line rates of 2000 kbps (command vbr-nrt 2000 2000 ), and VC3 has PCR and SCR line rates of 496 kbps (command vbr-rt 496 496 ), then when no oversubscription bandwidth is available, VC1 and VC 2 are configured with the specified PCR and SCR line rates, but VC3 is downgraded to UBR class.

If the DSL line rate goes down and comes back up with less than the trained rate (based on the trained bandwidth PVCs) and no bandwidth is left, some PVCs might be downgraded to UBR class.

The value of the oversubscription factor determines the maximum bandwidth that is configured, which is the sum of SCRs for all VBR-rt, VBR-nrt, and UBR+. PVCs. To disable oversubscription, the total configured bandwidth of CBR, VBR-rt, VBR-nrt, and UBR+ must not exceed actual trained bandwidth. The CBR bandwidth is counted when disabling oversubscription.

With oversubscription disabled, a PVC can be configured only up to the line rate. For example, if the line rate is 2304 kbps, the SCR or PCR of a VBR PVC cannot be more than 2304 kbps (assuming there are no other PVCs). If there is another PVC, such as a CBR PVC with a PCR of 500 kbps, that line rate is subtracted, and the maximum SCR or PCR allowed on the VBR PVC is 1804 kbps.

The first time VBR-rt, VBR-nrt, or UBR+ PVCs are configured with the oversubscription factor enabled, the available bandwidth is checked. If the required bandwidth is available, the service class commands (vbr-rt , vbr-nrt , and ubr+ ) are accepted. If there is not enough requested bandwidth, the service class commands are rejected, and the PVC state will be UP with service class set to UBR.

After VBR-rt, VBR-nrt, or UBR+ PVCs are configured, a dynamic line rate modification occurs when the atm oversubscribe factor command is enabled. The available bandwidth is checked, and if the required amount is available, the PVC state will be UP with the configured service class. If there is not enough bandwidth, the PVC state will be UP with service class UBR.

DSL ATM interfaces do not support switched virtual circuits (SVCs).

Usage Guidelines

Restrictions and Limitations for Interface Oversubscription

Because of a mismatch of rates between the packet scheduler and the network, interface oversubscription can degrade system performance during congestion.

With oversubscription, network congestion can occur if all of the network capacity is used concurrently. However, the risk is low if you avoid oversubscribing a network that is likely to congest and if you do not oversubscribe a service excessively.

The router uses the atm over-subscription-factor command in conjunction with the atm oversubscribe command to enable or disable oversubscription for a particular interface. When enabling ATM oversubscription for a particular interface, specify the atm over-subscription-factor command. Do not use the atm oversubscribe command to enable oversubscription, because this can cause undesirable results.

An ATM variable bit rate (VBR) VC uses the sustained cell rate (SCR) to define the VC’s average transmission rate. Therefore, use the atm over-subscription-factor command, but not the service-policy command, to specify the ATM VC oversubscription.

Because the oversubscription of VBR-nrt VCs requires resources from the entire line card, apply the atm over-subscription-factor command on all ports of the ATM interface (for example, the 4-port OC-3 ATM line card). If you enable oversubscription on only one port, the other ports might use more resources than they were configured to use. As a result, some ports might not receive adequate resources, which would cause VC creation failures.

Usage Guidelines

The atm pppatm passive command places PPP over ATM (PPPoA) sessions on an ATM subinterface in “listening” mode. Rather than trying to establish the sessions actively by sending out Link Control Protocol (LCP) packets, these sessions listen to the incoming LCP packets and become active only after they have received their first LCP packet. This feature is useful for L2TP access concentrators (LACs) in the broadband access deployments where thousands of PPPoA sessions are configured on LACs. When PPPoA is in the passive mode, the LAC brings up the sessions only when the subscribers become active and not use its processing power on polling all sessions.

For better scalability and faster convergence of PPP sessions, you should set the PPPoA sessions to passive mode at the LAC.

Cisco 10000 Series Router

For better scalability and faster convergence of PPPoA, PPP over Ethernet over ATM (PPPoEoA), or LAC sessions, set the sessions to passive mode.

You must use the atm pppatm passive command for large-scale PPP terminated aggregation (PPPoA and PPPoEoA) and Layer 2 Tunnel Protocol (L2TP) access concentrator (LAC). Instead of sending out LCP packets to establish the sessions actively, the sessions listen to the incoming LCP packets and become active only after they receive their first LCP packet. When PPPoX is in the passive mode, the LAC brings up the sessions only when the subscribers become active and does not use processing power polling all sessions.

Usage Guidelines

This command is commonly used to create a PVP that is used to multiplex circuit emulation service (CES) and data VCs.

The ATM-CES port adapter supports multiplexing of one or more VCs over a virtual path that is shaped at a constant bandwidth. For example, you can buy a virtual path service from an ATM service provider and multiplex both the CES and data traffic over the virtual path.

All subsequently created VCs with a vpi argument matching the vpi specified with the atm pvp command are multiplexed onto this PVP. This PVP connection is an ATM connection where switching is performed on the VPI field of the cell only.

A PVP is created and left up indefinitely. All VCs that are multiplexed over a PVP share and are controlled by the traffic parameters associated with the PVP.

Changing the peak-rate value causes the ATM-CES port adapter to go down and then back up.

When you create a PVP, two VCs are created (VCI 3 and 4) by default. These VCs are created for VP end-to-end loopback and segment loopback OAM support.

When you use the l2transport keyword with the atm pvp command, the router enters l2transport PVP configuration mode. You must issue the l2transport keyword to configure the ATM cell relay over multiprotocol label switching (MPLS) feature in port mode or to configure the ATM cell relay over L2TPv3 feature.

To verify the configuration of a PVP, use the show atm vp command.

Usage Guidelines

If a PVC or SVC is created, and its rate queue does not match a permanent rate queue that was created using the atm-rate queue queue-number speed command, one of the following will occur:

• The PVC or SVC will use an existing rate queue if the PVC’s or SVC’s rate queue falls within the tolerance-value specified.

• The software will dynamically create a new and unique rate queue if the PVC or SVC does not fall within a previously configured rate-queue tolerance.

If you do not create permanent rate queues or if you create PVCs with peak or average rates that are not matched by the rate queues you configure, the software dynamically creates rate queues as necessary to satisfy the requests of the atm pvc commands.

You can create multiple rate queues. A warning message appears if all rate queues are deconfigured or if the combined rate queues exceed the PLIM rate.

Usage Guidelines

This command is supported on the Cisco 7200 and 7500 series routers, but not on the Cisco 4500 and Cisco 4700 routers.

The raw queue is used for raw ATM cells, which include Operation, Administration, and Maintenance (OAM) (F4 and F5) and Interim Local Management Interface (ILMI) cells.

Usage Guidelines

This command is supported on 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.

Usage Guidelines

This command is supported on the Cisco 7500 series routers, Cisco 4500 routers, and Cisco 4700 routers. This command is not supported on the ATM port adapter.

If strict traffic shaping is configured on the router ATM interface, then an SVC is established only if traffic shaping can be provided for the transmit cell flow according to the signaled traffic parameters. If such shaping cannot be provided, the SVC is released.

If strict traffic shaping is not configured on the router ATM interface, an attempt is made to establish an SVC with traffic shaping for the transmit cell flow according to the signaled traffic parameters. If such shaping cannot be provided, the SVC is installed with default shaping parameters (it behaves as though a permanent virtual circuit (PVC) were created without specifying traffic parameters).

The signalling SETUP message carries the forward and backward traffic parameters. For connections initiated by the source router, traffic is shaped to the SETUP message forward parameters. For connections initiated by another router or host, traffic is shaped to the backward parameters.

Usage Guidelines

This command is supported on Cisco 7500 series routers, Cisco 4500 routers, and Cisco 4700 routers. This command is not supported on the ATM port adapter.

Each AAL3/4 subinterface is allowed only one unicast E.164 address.

Usage Guidelines

An S1 SONET overhead byte set to 0xF switches the clock source to internal; however, in the event that a packet is received with an S1 byte value of 0xF, the atm sonet ignore s1 command ensures that the clock source does not change.

Usage Guidelines

The atm sonet report command enables one or more of the possible SONET alarms that can be generated by the ATM interface. By default, only the PLOP, SLOF, and SLOS alarms are enabled, but you can enable the other alarms or all alarms, as well. You can also disable one or all of the alarms using the no form of the command.

Usage Guidelines

Use STM-1 in applications where the ATM switch requires “idle cells” for rate adaptation. An idle cell contains 31 zeros followed by a one. STM-1 is defined as a Synchronous Digital Hierarchy/Synchronous Transport Signal level 1 (SDH/STM-1) operation (ITU-T specification).

Use the default (STS-3c) in applications where the ATM switch requires “unassigned cells” for rate adaptation. An unassigned cell contains 32 zeros.