The following example shows how to verify the configuration for the 2-Port Channelized T3/E3 CEoP SPA:

Router# show controller t3 0/1/0
T3 0/1/0 is up.
  Hardware is SPA-2CHT3-CE-ATM
Applique type is Clear-channel T3 ATM
  No alarms detected.
  Framing is M23, Line Code is B3ZS, Cablelength is 224
  Clock Source is internal
  Equipment customer loopback
  Data in current interval (97 seconds elapsed):
     0 Line Code Violations, 0 P-bit Coding Violation
     0 C-bit Coding Violation, 0 P-bit Err Secs
     0 P-bit Severely Err Secs, 0 Severely Err Framing Secs
     0 Unavailable Secs, 0 Line Errored Secs
     0 C-bit Errored Secs, 0 C-bit Severely Errored Secs
     0 Severely Errored Line Secs
     0 Far-End Errored Secs, 0 Far-End Severely Errored Secs
     0 CP-bit Far-end Unavailable Secs
     0 Near-end path failures, 0 Far-end path failures
     0 Far-end code violations, 0 FERF Defect Secs
     0 AIS Defect Secs, 0 LOS Defect Secs
Router# show controller e3 0/1/0
E3 0/1/0 is up.
  Hardware is SPA-2CHT3-CE-ATM
Applique type is Clear-channel E3 ATM
  Receiver has loss of signal.
  Framing is E3 G751, Line Code is HDB3
  Clock Source is internal, National Bit 0
  Equipment customer loopback
  Data in current interval (363 seconds elapsed):
     0 Line Code Violations, 0 P-bit Coding Violation
     0 C-bit Coding Violation, 0 P-bit Err Secs
     0 P-bit Severely Err Secs, 0 Severely Err Framing Secs
     101 Unavailable Secs, 0 Line Errored Secs
     0 C-bit Errored Secs, 0 C-bit Severely Errored Secs
Router# show ip interface brief
Interface              IP-Address        OK?  Method    Status                Protocol
ATM0/1/0               Unassigned        YES  manual    up                    up
ATM0/1/1               Unassigned        YES  manual    up                    up

The following section displays the command outputs for the E3 mode:

Router# show interfaces ATM 0/1/0.1
ATM0/1/0.1 is up, line protocol is up
  Hardware is SPA-2CHT3-CE-ATM, address is 0026.cb0c.f410 (bia 0026.cb0c.f410)
  MTU 4470 bytes, BW 33791 Kbit/sec, DLY 0 usec,
     reliability 255/255, txload 1/255, rxload 1/255
  Encapsulation ATM
  Keepalive not supported
     0 packets input, 0 bytes
     0 packets output, 0 bytes
     0 OAM cells input, 0 OAM cells output
  AAL5 CRC errors : 0
  AAL5 SAR Timeouts : 0
  AAL5 Oversized SDUs : 0
  AAL5 length violation : 0
  Last clearing of "show interface" counters never
Router# show interfaces atm 0/1/0
ATM0/1/0 is up, line protocol is up
  Hardware is SPA-2CHT3-CE-ATM, address is 0026.cb0c.f410 (bia 0026.cb0c.f410)
  MTU 4470 bytes, sub MTU 4470, BW 33791 Kbit/sec, DLY 0 usec,
     reliability 255/255, txload 1/255, rxload 1/255
  Encapsulation ATM, loopback not set
  Keepalive not supported
  Encapsulation(s): AAL5 AAL0
  2047 maximum active VCs, 1 current VCCs
  VC Auto Creation Disabled.
  VC idle disconnect time: 300 seconds
  2 carrier transitions
  Last input never, output never, output hang never
  Last clearing of "show interface" counters never
  Input queue: 0/375/0/0 (size/max/drops/flushes); Total output drops: 0
  Queueing strategy: fifo
  Output queue: 0/40 (size/max)
  5 minute input rate 0 bits/sec, 0 packets/sec
  5 minute output rate 0 bits/sec, 0 packets/sec
     0 packets input, 0 bytes, 0 no buffer
     Received 0 broadcasts (0 IP multicasts)
     0 runts, 0 giants, 0 throttles
     0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
     0 packets output, 0 bytes, 0 underruns
     0 output errors, 0 collisions, 1 interface resets
     0 unknown protocol drops
     0 output buffer failures, 0 output buffers swapped out
Router# show atm pvc interface atm 0/1/0.1
           VCD /                                            Peak Av/Min Burst
Interface  Name         VPI   VCI Type    Encaps     SC     Kbps   Kbps Cells St
0/1/0.1    1            100    32 PVC     SNAP       UBR   33791      UP
Router# show atm interface atm 0/1/0
Interface ATM0/1/0:
AAL enabled:  AAL5, AAL0, Maximum VCs: 2047, Current VCCs: 1
Max. Datagram Size: 4528
PLIM Type: E3 - 34000Kbps, Framing is G.751 ADM, TX clocking: LINE
0 input, 0 output, 0 IN fast, 0 OUT fast
 Avail bw = 34368
Config. is ACTIVE
Router# show atm interface atm 0/1/0.1
Interface ATM0/1/0.1:
AAL enabled:  AAL5, AAL0, Maximum VCs: 2047, Current VCCs: 1
Max. Datagram Size: 4528
PLIM Type: E3 - 34000Kbps, Framing is G.751 ADM, TX clocking: LINE
0 input, 0 output, 0 IN fast, 0 OUT fast
 Avail bw = 34368
Config. is ACTIVE
Router# show atm pvc
VCD /                                            Peak Av/Min Burst
Interface  Name         VPI   VCI Type    Encaps     SC     Kbps   Kbps Cells St
0/1/0.1    1            100    32 PVC     SNAP       UBR   33791      UP

The following section displays the command outputs for the T3 mode:

Router# show atm interface atm 5/1/0
Interface ATM5/1/0:
AAL enabled: AAL5, AAL0, Maximum VCs: 2047, Current VCCs: 0
Max. Datagram Size: 4528
PLIM Type: DS3 - 45000Kbps, Framing is C-bit ADM,
DS3 lbo: short, TX clocking: LINE
Cell-payload scrambling: OFF
0 input, 0 output, 0 IN fast, 0 OUT fast
 Avail bw = 44209
New Config. not yet ACTIVE
Router# show atm pvc interface atm 5/1/1.1
VCD /                                            Peak Av/Min Burst
Interface  Name         VPI   VCI Type    Encaps     SC     Kbps   Kbps Cells St
5/1/1.1    1            100    34 PVC     SNAP       UBR   44209              UP
Router# show atm interface atm 5/1/1.1
Interface ATM5/1/1.1:
AAL enabled:  AAL5, AAL0, Maximum VCs: 2047, Current VCCs: 1
Max. Datagram Size: 4528
PLIM Type: DS3 - 45000Kbps, Framing is C-bit ADM,
DS3 lbo: short, TX clocking: LINE
Cell-payload scrambling: OFF
0 input, 0 output, 0 IN fast, 0 OUT fast
 Avail bw = 44209
Config. is ACTIVE
Router# show interfaces atm 5/1/1.1
ATM5/1/1.1 is up, line protocol is up
  Hardware is SPA-2CHT3-CE-ATM, address is e804.6227.3851 (bia e804.6227.3851)
  MTU 4470 bytes, BW 44209 Kbit/sec, DLY 0 usec,
     reliability 255/255, txload 1/255, rxload 1/255
  Encapsulation ATM
  Keepalive not supported
     0 packets input, 0 bytes
     0 packets output, 0 bytes
     0 OAM cells input, 0 OAM cells output
  AAL5 CRC errors : 0
  AAL5 SAR Timeouts : 0
  AAL5 Oversized SDUs : 0
  AAL5 length violation : 0
  Last clearing of "show interface" counters never
Router# show interfaces atm 5/1/1
ATM5/1/1 is up, line protocol is up
  Hardware is SPA-2CHT3-CE-ATM, address is e804.6227.3851 (bia e804.6227.3851)
  MTU 4470 bytes, sub MTU 4470, BW 44209 Kbit/sec, DLY 0 usec,
     reliability 255/255, txload 1/255, rxload 1/255
  Encapsulation ATM, loopback not set
  Keepalive not supported
  Encapsulation(s): AAL5 AAL0
  2047 maximum active VCs, 1 current VCCs
  VC Auto Creation Disabled.
  VC idle disconnect time: 300 seconds
  2 carrier transitions
  Last input never, output never, output hang never
  Last clearing of "show interface" counters never
  Input queue: 0/375/0/0 (size/max/drops/flushes); Total output drops: 0
  Queueing strategy: fifo
  Output queue: 0/40 (size/max)
  5 minute input rate 0 bits/sec, 0 packets/sec
  5 minute output rate 0 bits/sec, 0 packets/sec
     0 packets input, 0 bytes, 0 no buffer
     Received 0 broadcasts (0 IP multicasts)
     0 runts, 0 giants, 0 throttles
     0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
     0 packets output, 0 bytes, 0 underruns
     0 output errors, 0 collisions, 1 interface resets
     0 unknown protocol drops
     0 output buffer failures, 0 output buffers swapped out

The following section displays the command output for the CEM mode:

Router# show interfaces cem 0/3/0
CEM0/3/0 is up, line protocol is up
  Hardware is Circuit Emulation Interface
  MTU 1500 bytes, BW 45000 Kbit/sec, DLY 0 usec,
     reliability 255/255, txload 2/255, rxload 8/255
  Encapsulation CEM, loopback not set
  Keepalive not supported
  Last input never, output never, output hang never
  Last clearing of "show interface" counters never
  Input queue: 0/375/0/0 (size/max/drops/flushes); Total output drops: 0
  Queueing strategy: fifo
  Output queue: 0/0 (size/max)
  5 minute input rate 1536000 bits/sec, 1000 packets/sec
  5 minute output rate 425000 bits/sec, 278 packets/sec
     4708356 packets input, 904004352 bytes, 0 no buffer
     Received 0 broadcasts (0 IP multicasts)
     0 runts, 0 giants, 0 throttles
     0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
     100747 packets output, 19343424 bytes, 0 underruns
     0 output errors, 0 collisions, 0 interface resets
     0 unknown protocol drops
     0 output buffer failures, 0 output buffers swapped out

Consider the following guideline before configuring the ATM connections on a SPA:

In the clear-channel mode, each port in the 2-Port Channelized T3/E3 ATM CEoP SPA provides a single ATM connection operating at the T3line rate.

Consider the following guideline before configuring the ATM connections on a SPA:

In the clear-channel mode, each port in the 24-Port Channelized T1/E1 ATM CEoP SPA provides a single ATM connection operating at the T1/E1 line rate.

Configuring an ATM Interface

A Cisco ASR 1000 Series Aggregation Services Router creates an ATM interface for each T1/E1port that is configured for the ATM. The interface is in the atm slot /subslot /port format, where slot /subslot identifies the SPA slot and subslot, and /port identifies the port, for example, atm 2/1/0 .

The ATM configuration for SPA-24CHT1-CE-ATM is the same as the ATM configuration for SPA-2CHT3-CE-ATM. For more information about the ATM configuration for SPA-2CHT3-CE-ATM, see the Configuring the Card Type for the 2-Port Channelized T3/E3 ATM CEoP SPA.

Note	The SPA-24CHT1-CE-ATM is supported both T1 and E1 modes.

Local Switching Redundancy guidelines are as follows:

• Autoconfiguration of CEM interfaces is not supported.
• Only the tail-end AC can be backed up. If head end fails, there is no protection.
• The circuit type of the primary and backup AC must be identical (failover operation will not switch between different types of interfaces or different CEM circuit types).
• Backs up a local switching connection to cem-ckt3 of CEM interface cem3. Only one backup AC is allowed for each connection.
• Auto configuration of backup CEM circuits is not allowed.
• The CEM circuit that is used as a backup in a local switching connection cannot be used for Xconnect configurations.
• Dynamic modification of parameters in a local switching connection is not supported in a scenario where the tail-end segment is backed up to a segment using the backup command. If you want to modify the parameters in any of the three segments (head-end, tail-end, or backup), you must first unconfigure with the backup command, make the changes in the individual segments, and then reconfigure the backup with the backup command.

Use the show xconnect all command to check the status of the backup and primary circuits.

To configure the network clock, consider the following guidelines:

• The Cisco ASR 1000 Series Aggregation Services Routers operate in the free-running mode until the network clock is configured.
• When the network clocking configuration is present in the startup configuration, the clocking configuration is not applied until five minutes after the configuration has been parsed. This prevents clocking instability on the backplane when the interfaces or controllers come up out of order.
• Network clocking is enabled by default for the Cisco ASR 1000 Series Aggregation Services Routers.
• If there is a source flap, an interval of 180 seconds exists before the source becomes valid and active.
• In the event of an Out-of-Range (OOR) switchover (revertive mode), the source switchover occurs when the clock offset crosses the -9.2 ppm or +9.2 ppm threshold. If OOR switchover occurs, you must reconfigure the source.

Use the show network-clocks command to verify the output on the RP:

Router# show network-clocks 
 Active source = SONET 0/1/0
 Active source backplane reference line = Primary Backplane Clock
 All Network Clock Configuration
---------------------------------
 Priority    Clock Source             State                            Reason
 1           SONET 0/1/0              Valid                         
 Current operating mode is Revertive 
 Current OOR Switchover mode is Switchover 
There are no slots disabled from participating in network clocking

Out-of-band clocking provides the following benefits:

• Enables mobile wireless providers to migrate from TDM networks to PSNs in order to save on costs and improve scalability.
• CEM SPA equipment can ignore the contents of the timing packets that are sent over the out-of-band clock channel because the packets do not contain data.
• Uses the CEM SPA for applications that use something other than constant bit rate (CBR) data. For example, out-of-band clocking uses the SPA for 3G (data) wireless applications, which use AAL2 in variable bit rate (VBR) mode. In addition, out-of-band clocking uses the SPA for 2G (voice) applications.
• Provides recovered clock accuracy that complies with ITU-T G.823 and G.824 specifications, which enables the CEM SPA to be used in mobile and wireless applications (including voice) that require extreme synchronization accuracy.
• Provides an alternative clock-recovery mechanism when adaptive clocking cannot be deployed.
• Enables the CEM SPA to be the master clock in a PSN.
• Makes it possible to have two master clocks. Previously, only one master clock was possible.

The following guidelines apply to out-of-band clocking on CEM SPA:

• The default packet size for out-of-band clock channels (CEM circuits) is 910 bytes.
• Out-of-band clocking can co-exist with Stateful SwitchOver (SSO), but it is not SSO compliant. Therefore, if a switchover occurs, the out-of-band clocking functionality is not available for a brief period of time while the feature is brought back online.
• A CEM SPA cannot be configured as both a master and slave clock. To reconfigure a SPA’s clock type, you must first remove the existing clock configuration (master or slave).
• Pseudowires for out-of-band clocking are configured under the virtual CEM interface that represents the recovered clock interface. This process differs from normal CEM pseudowires, which are configured under the port (controller interface). When no network clock is available, the virtual CEM interface goes down and the pseudowire is disabled. This process is reversed when a valid network clock becomes available again. Normal CEM interfaces never go down, even if the associated physical link is down.
• The master clock pseudowire and slave clock pseudowire should be on different CEM SPAs.

The following section provides a high-level overview of the procedure for configuring out-of-band clocking between two CEM SPAs. Detailed steps are provided in the sections that follow.

Before you begin, determine which CEM SPAs have TDM devices connected to them. You must configure an out-of-band clock channel to deliver the clock signal from each SPA that sends TDM data to every destination SPA that receives the data.

1. Use the recovered clock command to identify the CEM SPA that is to send TDM data across the MPLS network. This SPA’s clock is used as the master clock for out-of-band clocking.
2. Configure the master and slave clock interfaces to represent the source (clock master) and destination (clock slave) for the out-of-band clock signal. The master and slave clock interfaces (and pseudowires) should be configured on different SPAs.
   1. Configure the master clock interfac. This interface represents the master clock, which is distributed to all the destination CEM SPAs that receive data from the source TDM device connected to this SPA. (See the Creating the Master Clock Interface for instructions.)
   2. Configure a slave clock interface on each of the SPAs connected to the TDM devices that can receive data from the source TDM device. (See the Configuring the Slave Clock Interface for detailed instructions.)

Note

When you configure a master or slave clock interface, the router creates a virtual CEM interface to represent this out-of-band clock. The virtual CEM interface has the same slot and subslot information as the CEM SPA from which the master clock is recovered. The port number is always 24. For example, if the clock signal is recovered from the SPA in slot 0, subslot 1 (recovered-clock 0 1 ), the virtual CEM interface is virtual-cem0/1/24.

1. Under both the master and slave clock interfaces, use the cem circuit-id command to configure CEM circuits to represent the out-of-band channels that will distribute the clock signal over the MPLS network. Each CEM circuit represents a separate out-of-band channel for delivering the clock signal from the source (master clock) to a destination TDM device (slave clock). The out-of-band clock channel is created when you issue the xconnect command in the next step.
   • Under the master clock interface, you can configure up to 64 CEM circuits, one for each of the destination TDM devices that will use this clock signal as its master clock.
   • Under the slave clock interface (on the destination TDM device), you can configure one or two CEM circuits. Two CEM circuits are allowed because the clock slave can receive a clock signal from two master clocks.

Note	Each out-of-band clock channel requires two CEM circuits (one on the master clock interface and one on the slave clock interface). Each CEM circuit represents the CEM attachment circuit at one end of the out-of-band clock channel.

1. Create the out-of-band channel for the clock signal by using the xconnect command to configure two pseudowires between the CEM circuit on the master clock interface and the CEM circuit on the slave clock interface. The master clock pseudowire and slave clock pseudowire should be on different SPAs; however, you should use the same VCID for both pseudowires.
   1. Under the master clock interface, configure a pseudowire to the destination device (slave clock).
   2. Under the slave clock interface (on the SPA that connects to the destination TDM device), configure a pseudowire to the router that contains the master clock interface.

This section lists the show commands that you can use to verify the out-of-band clocking configuration.

• Use the show ip interface brief command to display the virtual CEM interfaces that the router created to represent master and slave clock interfaces. The output in the following example shows only the virtual CEM interface. Information for all other interfaces is omitted from the display.

Router# show ip int brief
 
. . .
Virtual-cem0/1/24 unassigned      YES unset  up                    up
. . .

• Use the show cem circuit command to display a list of CEM circuits configured on the SPA. The command displays both normal and out-of-band clocking CEM circuits.

Router# show cem circuit
 
CEM Int.       ID   Line      Admin     Circuit         AC 
-------------------------------------------------------------- 
CEM0/1/0 1    DOWN      DOWN      Active          --/--
Virtual-cem0/1/24 DOWN      UP        Active           UP 

• Use the show cem interface virtual-cem slot /subslot /port command to display information about a particular virtual CEM interface:

Router# show cem interface virtual-cem 0/1/24
 
(Virtual-cem0/1/24) State: CONFIG COMPLETE
Virtual CEM Slave Clock Interface
Slot 0, Slot Unit 88, VC -1
Total cem circuits:    1
Cem circuits up   :    1
Cem circuits down :    0

• Use the show run interface virtual-cem slot /subslot /port command to display the current running configuration pertaining to the specified interface:

Router# show run int virtual-cem 0/1/24
 
Building configuration...
Current configuration : 117 bytes
!
interface Virtual-cem0/1/24
 no ip address
 cem 1
xconnect 20.0.0.1 300 encapsulation mpls
 !
end

• Use the show run | begin recovered command to display the recovered clock used for out-of-band clocking:

Router# show run | begin recovered
 
recovered-clock 0 1 
 clock master 

• On the clock slave, you can use the show recovered-clock command to display the status of the out-of-band clock:

Router# show recovered-clock
 
Recovered clock status for subslot 0/1
----------------------------------------
Clock    Mode         Port CEM  Status     Frequency Offset(ppb)      
ENHANCED PRIMARY           0    HOLDOVER   0       

Use the following commands to delete the various components used for out-of-band clocking:

• To remove a CEM circuit, use the no cem circuit-id command (where circuit-id is the number assigned to the circuit). Issue the command under the virtual CEM interface where the circuit exists.

Router# conf t
 
Enter configuration commands, one per line.  End with CNTL/Z.
Router(config)# int virtual-cem 0/1/24
 
Router(config-if)# no cem 1
 
Router(config-if)# end
 

• To remove a virtual CEM interface, use the no clock master or no clock slave command in recovered-clock configuration mode, as shown in the following examples. Note that the virtual CEM interface is not deleted when you remove the last CEM circuit under the interface.

Router# conf t
 
Enter configuration commands, one per line.  End with CNTL/Z.
Router(config)# recovered-clock 0 1
 
Router(config-clock)# no clock master
 
Router(config-clock)# end
 
Router#

In the following example, the no clock slave command deletes the slave clock interface for the recovered clock (which is 0/1):

Router# config t
 
Enter configuration commands, one per line. End with CNTL/Z.
Router(config)# recovered-clock 0 1
 
Router(config-clock)# no clock slave
 
Router(config-clock)# end
 
Router#