Guest

Cisco MGX 8200 Series Edge Concentrators

CESM-8 Unstructured Data Transport

Document ID: 22236

Updated: Apr 30, 2009

   Print

Introduction

This document provides configuration examples for unstructured data transport on the Circuit Emulation Service Module-8 (CESM-8) card.

Prerequisites

Requirements

Before attempting this configuration, ensure that you are knowledgeable of:

  • Cisco CESM-8

  • Cisco MGX 8220

  • Cisco MC3810

Components Used

The information in this document is based on these software and hardware versions:

  • MGX 8220/8250 firmware 4.1.x and later supports the CESM-8T1E1 card set

All configuration examples in this document are based on a CESM-8 card with this firmware/bootcode/hardware revision:

wss-mgxb.1.10.CESM.a > dspcd
        ModuleSlotNumber: 10
        FunctionModuleState: Active
        FunctionModuleType: CESM-8T1
        FunctionModuleSerialNum: 754950
        FunctionModuleHWRev: aa
        FunctionModuleFWRev: 4.1.01
        FunctionModuleResetReason: Local DRAM parity reset
        LineModuleType: LM-RJ48-8T1
        LineModuleState: Present
        mibVersionNumber: 20
        configChangeTypeBitMap: CardCnfChng, LineCnfChng
        cardIntegratedAlarm: Clear
        fab number: 28-2199-02

The MC3810 multiservice access concentrator units used in the configuration examples as the customer premises equipment (CPE) devices are based on this software/hardware release level:

wss-3810a# show version 
    Cisco Internetwork Operating System Software 
    IOS (tm) MC3810 Software (MC3810-A2INR3V2-M), Version 11.3(1)MA62, EARLY DEPLOY 
    Copyright (c) 1986-1998 by cisco Systems, Inc.
    Compiled Mon 26-Oct-98 19:35 by runyan 
    Image text-base: 0x00023000, data-base: 0x0064BFDC 

    ROM: System Bootstrap, Version 11.3(1)MA1, MAINTENANCE INTERIM SOFTWARE 
    ROM: MC3810 Software (MC3810-WBOOT-M), Version 11.3(1)MA1, MAINTENANCE INTERIM 

    wss-3810a uptime is 3 days, 1 hour, 20 minutes 
    System restarted by reload 
    System image file is "flash:mc3810-a2inr3v2-mz.113-1.MA62", booted via flash: 

    Cisco MC3810 (MPC860) processor (revision 06.07) with 27648K/5120K bytes of mem. 
    Processor board ID 09502861 
    PPC860 PowerQUICC, partnum 0x0000, version A03(0x0013) 
    Bridging software. 
    MC3810 SCB board (v05.A0) 
    1 Multiflex T1(slot 3) RJ45 interface(v01.K0) 
    1 Multiflex T1(slot 4) RJ45 interface(v01.K0) 
    1 6-DSP(slot2) Voice Compression Module(v01.K0) 
    1 6-DSP(slot5) Voice Compression Module(v01.K0) 
    1 Ethernet/IEEE 802.3 interface(s) 
    4 Serial network interface(s) 
    2 Channelized T1/PRI port(s) 256K bytes of non-volatile configuration memory. 
    8192K bytes of processor board System flash (INTEL28F016)

    Configuration register is 0x2102 

wss-3810a#

The information in this document was created from the devices in a specific lab environment. All of the devices used in this document started with a cleared (default) configuration. If your network is live, make sure that you understand the potential impact of any command.

Conventions

For more information on document conventions, refer to the Cisco Technical Tips Conventions.

Background Information

The CESM-8 card offers a 100 percent port density increase over the CESM-4 card, as well as various clocking and framing functional enhancements. The CESM-4 card supports only T1/E1 basic unstructured service with synchronous clocking. The CESM-8 provides both basic unstructured service and basic/channel associated signaling (CAS) structured service.

This document explores only the unstructured service features of the CESM-8 card, particularly the clocking schemes (synchronous, Synchronous Residual Time Stamp (SRTS), and adaptive), and the framingonVCdisconnect feature. Refer to these specifications for more background information on Circuit Emulation or Unstructured Data Transport:

Configure

The CESM-8 supports both T1 and E1 lines. Both line types are configured using the same set of commands.

  • Lines are the first entity to be configured on the card.

  • Next, logical ports are configured and associated with the active lines. These ports define a range of digital signal level 0s (DS0s) to use on the card and the type of CES to use (structured or unstructured).

  • Finally, channels are created for each port to route the data through the ATM network.

This section describes these configurations:

Note: To find additional information on the commands used in this document, use the Command Lookup Tool (registered customers only) .

Synchronous Clocking

In this example, we connect the MC3810 units WSS-3810A and WSS-3810B via their MultiFlex Trunk (MFT) modules (Controller T1 0/Serial 2) using High-Level Data Link Control (HDLC) as the layer 2 protocol. Each multiflex trunk module (MFT) connects into Line 2 on its respective CESM card. All devices in the test network derive their timing from the internal oscillator on WSS-BPXC.

This example uses this network diagram:

UDT-Synchronous.gif

  1. CESM—Build Lines

    Bring up the lines on the two CESM cards. The line configuration covers the physical layer parameters for the associated T1 or E1 line.

    MGX-B
    wss-mgxb.1.10.CESM.a > addln 2
    
    wss-mgxb.1.10.CESM.a > dsplns
    Line Conn    Type       Status/Coding    Length       XmtClock Alarm Stats
         Type                                              Source        Alarm
    ---- ----- ------------ ------ -------- ------------- -------- ----- -----
    10.1 RJ-48 dsx1ESF      Dis/dsx1B8ZS    0-131 ft      LocalTim 
    10.2 RJ-48 dsx1ESF      Ena/dsx1B8ZS    0-131 ft      LocalTim  No    No 
    10.3 RJ-48 dsx1ESF      Dis/dsx1B8ZS    0-131 ft      LocalTim 
    10.4 RJ-48 dsx1ESF      Dis/dsx1B8ZS    0-131 ft      LocalTim 
    10.5 RJ-48 dsx1ESF      Dis/dsx1B8ZS    0-131 ft      LocalTim 
    10.6 RJ-48 dsx1ESF      Dis/dsx1B8ZS    0-131 ft      LocalTim 
    10.7 RJ-48 dsx1ESF      Dis/dsx1B8ZS    0-131 ft      LocalTim 
    10.8 RJ-48 dsx1ESF      Dis/dsx1B8ZS    0-131 ft      LocalTim 
          
    wss-mgxb.1.10.CESM.a > dspln 2
    LineNum:                   2
    LineConnectorType:         RJ-48
    LineEnable:                Enabled
    LineType:                  dsx1ESF
    LineCoding:                dsx1B8ZS
    LineLength:                0-131 ft
    LineXmtClockSource:        LocalTiming
    LineLoopbackCommand:       NoLoop
    LineSendCode:              NoCode
    LineUsedTimeslotsBitMap:   0xffffff
    LineLoopbackCodeDetection: codeDetectDisabled

    MGX-C
    wss-mgxc.1.10.CESM.a > addln 2
    

  2. CESM—Configure Ports

    Add the logical ports. Ports provide a logical grouping for a series of DS0s on a particular line and define the CES mode. With unstructured service, all DS0s for a line are subsumed in one port.

    MGX-B
    wss-mgxb.1.10.CESM.a > addport 21 2 1 24 2
          
    wss-mgxb.1.10.CESM.a > dspport 21
     SlotNum:                     10
     PortLineNum:                 2
     PortNum:                     21
     PortRowStatus:               Add
     PortNumOfSlots:              24
     PortDs0ConfigBitMap(1stDS0): 0xffffff(1)
     PortSpeed:                   1544kbps
     PortType:                    unstructured
     PortState:                   Active

    MGX-C
    wss-mgxc.1.10.CESM.a > addport 22 2 1 24 2
    

  3. CESM—Add Channels

    The logical channel controls the ATM side parameters for the connection. Link one logical channel to one logical port. Here, we configure the ports for basic service (channel associated signaling (CAS) is not appropriate for unstructured data transport), and set the conditioning criteria to send all 1s if the channel experiences cell loss. We then configure the channel buffer size, Cell Delay Variation Tolerance (CDVT), and clocking values.

    MGX-B
    wss-mgxb.1.10.CESM.a > addchan 121 21 1 0 255 15
          
    wss-mgxb.1.10.CESM.a > cnfchan 121 1000 1000 0 1 1 1 
          
    wss-mgxb.1.10.CESM.a > dspchan 121
     ChanNum:                  121
     ChanRowStatus:            Mod
     ChanLineNum:              2
     ChanMapVpi:               10
     ChanMapVci:               121
     ChanCBRService:           unstructured
     ChanClockMode:            Synchronous
     ChanCAS:                  Basic
     ChanPartialFill:          47
     ChanMaxBufSize:           384 bytes
     ChanCDV:                  1000 micro seconds
     C L I P:                  1000 milliseconds
     ChanLocalRemoteLpbkState: Disabled
     ChanTestType:             TestOff
     ChanTestState:            NotInProgress
     ChanRTDresult:            65535 ms
     ChanPortNum               21
     ChanConnType              PVC
     ISDetType                 DetectionDisabled
     CondData                  255
     CondSignalling            15
     ExtISTrig                 DisableIdleSupression
     ISIntgnPeriod             4095 seconds 
     ISSignallingCode          0
     OnHookCode                1

    MGX-C
    wss-mgxc.1.10.CESM.a > addchan 122 22 1 0 255 15
    
    wss-mgxc.1.10.CESM.a > cnfchan 122 1000 1000 0 1 1 1
    

  4. CESM—Examine Channel Statistics

    # If we look at the channel statistics at this stage of the configuration, we see some definite problems. The associated channel on each card appears to be sending cells into the network, but neither channel reports receiving any cells, thus the alarm condition for the channel state. The problem here is that we have not built the permanent virtual circuit (PVC) to transport the AAL1 cells from CESM card to CESM card.

    MGX-B
    wss-mgxb.1.10.CESM.a > clrchancnts
          
    wss-mgxb.1.10.CESM.a > dspchancnt 121
     ChanNum:                  121
     Chan State:               alarm
     Chan RCV ATM State:       Normal
     Chan XMT ATM State:       Normal
     Cell Loss Status:         Cell Loss
     Reassembled Cells:        0
     Generated Cells:          158171
     Header Errors:            0
     Seqence Mismatches:       0
     Lost Cells:               0
     Channel Uptime (secs.)    186
     Signalling Status         Offhook

  5. BPX—Add CBR Connection

    In order to carry the cells from one CESM to the other, we need to build a constant bit rate (CBR) connection from the BXM trunk cards off of which each MGX shelf hangs. Because this PVC will carry a T1 unstructured stream, we configure the cell rate at 4107 cells per second.

    (193 bits/frame * 8000 frames/sec) / (47 bytes/cell * 8 bits/byte) = 4106.38 cells/sec

    BPX-B
    wss-bpxb     TN     StrataCom     BPX 8600     9.1.04     Nov. 13 1998     14:54 EST 
          
     Local        Remote        Remote                               Route
     Channel      NodeName      Channel      State       Type        Avoid     COS O
     3.1.10.121   wss-bpxc      10.1.10.122  Ok          cbr                    0  L
          
    Last Command: addcon 3.1.10.121 wss-bpxc 10.1.10.122 cbr 4107 * 1000 * Y
          
    ---------------------------------------------------------------------------
          
    wss-bpxb     TN     StrataCom     BPX 8600     9.1.04     Nov. 13 1998     15:41 EST 
          
    Conn: 3.1.10.121       wss-bpxc  10.1.10.122          cbr        Status:OK
       PCR(0+1)    % Util    CDVT(0+1)   Policing 
       4107/4107  100/100    1000/1000     4/4
    Owner: LOCAL  Restriction: NONE   COS: 0
    Trunk Cell Routing Restrict: Y
    Path:   wss-bpxb 1.1-- 1.1wss-bpxc
    Pref:   Not Configured
          
    wss-bpxb      BXM      : OK         wss-bpxc     BXM       : OK
                  Line 3.1 : OK                      Line 10.1 : OK
                  OAM Cell RX: Clear                 NNI       : OK
                  NNI      : OK
          
    Conn:   3.1.10.121       wss-bpxc     10.1.10.122    cbr     Status:OK
       PCR(0+1)     % Util       CDVT(0+1)       Policing
       4107/4107    100/100      1000/1000          4
          
    Trunk Cell Routing Restrict: Y
          
    Last Command: dspcon 3.1.10.121
    

  6. CESM—Monitor Connection Statistics

    Now when we look at the channel counters on the CESM card; things look much better. The key thing to notice is that the connections are not in alarm, and the cells in and out are, for all intents and purposes, the same.

    MGX-B
    wss-mgxb.1.10.CESM.a > clrchancnts
     
    wss-mgxb.1.10.CESM.a > clrsarcnts
     
    wss-mgxb.1.10.CESM.a > dspchancnt 121
    ChanNum:                   121
    Chan State:                okay
    Chan RCV ATM State:        Normal
    Chan XMT ATM State:        Normal
    Cell Loss Status:          No Cell Loss
    Reassembled Cells:         40401
    Generated Cells:           40401
    Header Errors:             0
    Seqence Mismatches :       0
    Lost Cells:                0
    Channel Uptime (secs.)     345
    Signalling Status          Offhook
     
    wss-mgxb.1.10.CESM.a > dspsarcnt 121
                              SarShelfNum:         1
                              SarSlotNum:          10
                              SarChanNum:          121
                                    Tx                      Rx
                              ---------------       ---------------
      Total Cells:            85571                 85571
      Total CellsCLP:         0                     0
      Total CellsAIS:         0                     0
      Total CellsFERF:        0                     0
      Total CellsEnd2EndLpBk: 0                     0
      Total CellsSegmentLpBk: 0                     0
      RcvCellsDiscOAM:                              0

  7. BPX—Monitor Connection Statistics

    Again, the key point to notice in this screen is that the cells port-to-net and net-to-port are the same. If you ever see the Avg CPS above the PCR for the connection, the %util above 100, or any of the dscd counters clocking up, you probably have not calculated the correct PCR for the data stream.

    BPX-B
    wss-bpxb       TN    StrataCom       BPX 8600  9.1.04    Nov. 13 1998 14:57 EST 
     
    Channel Statistics for 3.1.10.121  Cleared: Nov. 13 1998 14:57  (-)
    PCR: 4107/4107 cps      Collection Time: 0 day(s) 00:00:33      Corrupted: NO
       Traffic      Cells      CLP      Avg CPS   %util  Chan Stat Addr: 31132770
    From Port   :    137416          0     4106      99
    To Network  :    137416    ---         4106      99
    From Network:    137416          0     4106      99
    To Port     :    137416          0     4106      99
                                                                                    
    Rx Frames Rcv :         0  NonCmplnt Dscd:         0  Rx Q Depth    :         0
    Tx Q Depth    :         0  Rx CLP0       :    137416  Rx Nw CLP0    :    137416
    Igr VSVD ACR  :         0  Egr VSVD ACR  :         0  Tx Clp 0      :    137416
    Rx Clp 0+1    :    137416  Tx Clp 0 Dscd :         0  Tx Clp 1 Dscd :         0
    Tx Clp0+1 Dscd:         0
     
    This Command: dspchstats 3.1.10.121 1
    

  8. Verify Clocking

    The clocking arrangement in this example has all units tracing their clock to the internal oscillator on WSS-BPXC. Since BPXC is the highest routing node in the network, BPXB automatically takes its clock from BPXC. Each MGX shelf is configured to time its bus inband from its BNM card. The lines on both CESM cards are local timed. And, each MC3810 is configured to time its internal bus using the recovered clock from the MFT. The MFTs do not show any clock slips, so timing looks good end-to-end (and we chose the MC3810s because they are very picky about their timing).

    BPX-B
    wss-bpxb       TN    StrataCom       BPX 8600  9.1.04    Nov. 13 1998 15:28 EST 
     
                                 Current Clock Source
     
    Source Node:     wss-bpxc
    Source Line:     Internal (CC)
     
    Clock Type:                 
    Clock Frequency: 1544000
     
    Path to Source:
       wss-bpxb 1.1--wss-bpxc
     
    Last Command: dspcurclk
    

    MGX-B
    wss-mgxb.1.3.ASC.a > dspclksrc
      PrimaryClockSource:   Inband from BNM
      SecondaryClockSource: Internal Oscillator
      CurrentClockSource:   Primary
      ClockSwitchState:     NoChange
      ExtClkPresent:        Not Present
      ExtClkSrcImpedance:   100 ohms
      ExtClkConnectorType:     DB-15

    MGX-C
    wss-mgxc.1.4.ASC.a > dspclksrc 
      PrimaryClockSource:   Inband from BNM
      SecondaryClockSource: Internal Oscillator
      CurrentClockSource:   Primary
      ClockSwitchState:     NoChange
      ExtClkPresent:        Not Present
      ExtClkSrcImpedance:   75 ohms
      ExtClkConnectorType:  BNC

    3810-A
    wss-3810a# show network-clocks 
    Priority 1 clock source(desired config): T1 0
    Priority 1 clock source(run-time config): T1 0
    Clock switch delay: 10
    Clock restore delay: 10
    T1 0 is clocking system bus for 1078 seconds.
    Run Priority Queue:  controller0,
     
    wss-3810a# show cont t1 0
    T1 0 is up.
      No alarms detected.
      Framing is ESF, Line Code is B8ZS, Clock Source is Line.
      Data in current interval (17 seconds elapsed):
         0 Line Code Violations, 0 Path Code Violations
         0 Slip Secs, 0 Fr Loss Secs, 0 Line Err Secs, 0 Degraded Mins
         0 Errored Secs, 0 Bursty Err Secs, 0 Severely Err Secs, 0 Unavail Secs

    3810-C
    wss-3810c# show network-clocks
    Priority 1 clock source(desired config): T1 0
    Priority 1 clock source(run-time config): T1 0
    Clock switch delay: 10
    Clock restore delay: 10
    T1 0 is clocking system bus for 1161 seconds.
    Run Priority Queue:  controller0,
          
    wss-3810c# show cont t1 0
    T1 0 is up.
      No alarms detected.
      Framing is ESF, Line Code is B8ZS, Clock Source is Line.
      Data in current interval (53 seconds elapsed):
         0 Line Code Violations, 0 Path Code Violations
         0 Slip Secs, 0 Fr Loss Secs, 0 Line Err Secs, 0 Degraded Mins
         0 Errored Secs, 0 Bursty Err Secs, 0 Severely Err Secs, 0 Unavail Secs

  9. MC3810 Configurations

    The relevant portions of the 3810 configuration files are shown below. Note that Controller T1 0 is the MFT and ties into the Serial 2 interface on the device. The default clock source on the T1 controllers is Line. In order to prevent timing problems on a 3810 with a DVM module (Controller T1 1), set the clock source on that controller so that both controllers are not trying to time the bus.

    3810-A
    wss-3810a# wr t
    Building configuration...
     
    Current configuration:
    !
    version 11.3
    !
    hostname wss-3810a
    !
    network-clock base-rate 64k
    network-clock-select 1 T1 0
    !
    controller T1 0
     framing esf
     linecode b8zs
     channel-group 0 timeslots 1-24 speed 64
    !
    controller T1 1
     framing esf
     clock source loop-timed
     linecode b8zs
    !
    interface Serial2
     ip address 10.97.100.1 255.255.255.0
    !
    end

    3810-C
    wss-3810c# wr t
    Building configuration...
     
    Current configuration:
    !
    version 11.3
    !
    hostname wss-3810c
    !
    network-clock base-rate 64k
    network-clock-select 1 T1 0
    !
    controller T1 0
     framing esf
     linecode b8zs
     channel-group 0 timeslots 1-24 speed 64
    !
    controller T1 1
     framing esf
     clock source loop-timed
     linecode b8zs
    !
    interface Serial2
     ip address 10.97.100.2 255.255.255.0
    !
    end

Synchronous Residual Time Stamp (SRTS) Clocking

Unfortunately, all network configurations do not allow all devices to trace their clock source to one reference. For those situations when the end devices are not in a position to take clock from the network, SRTS clocking allows timing to pass through the network.

SRTS operates under these assumptions:

  • All elements in the network portion of the Circuit Emulation Service (CES) can trace their clock to one reference.

  • CPE can also trace their clock to one reference.

Obviously, the CPE and network clock sources are different references. If they were the same, we would be using synchronous clocking.

This example uses the same configuration used in the synchronous clocking example, but we modify the channel parameters on the CESM cards to use SRTS, as opposed to synchronous timing. Then, we modify one of the MC3810 units to take timing from its internal oscillator. The other MC3810 unit continues to take its timing from the line.

UDT-SRTS.gif

  1. 1. CESM—Modify Channels for SRTS Clocking

    MGX-B
    wss-mgxb.1.10.CESM.a > cnfchan 121 1000 1000 0 2 1 1
    
    wss-mgxc.1.10.CESM.a > cnfchan 122 1000 1000 0 2 1 1
    

  2. MC3810—Change Clock Source on 3810-A

    MGX-B
    wss-3810a# conf t
    Enter configuration commands, one per line.  End with CNTL/Z.
    wss-3810a(config)# no network-clock-select 1 T1 0
    wss-3810a(config)# network-clock-select 1 system(SCB) 
    wss-3810a(config)#
    %MC3810_DSX1-5-MC3810_NOTICE: system(SCB) clocking PCM Bus
    %MC3810_DSX1-5-MC3810_NOTICE: system(SCB) clocking PCM Bus
     
    wss-3810a(config-controller)# cont t1 0
    wss-3810a(config-controller)# clock source internal
    wss-3810a(config-controller)# ^Z
    wss-3810a#
    %SYS-5-CONFIG_I: Configured from console by console
    wss-3810a#

  3. MC3810—Verify Clocking

    3810-A
    wss-3810a# show network-clocks 
    Priority 1 clock source(desired config): system(SCB)
    Priority 1 clock source(run-time config): system(SCB)
    Clock switch delay: 10
    Clock restore delay: 10
    system(SCB) is clocking system bus for 51 seconds.
    Run Priority Queue:  system(SCB),
     
    wss-3810a# show cont t1 0
    T1 0 is up.
      No alarms detected.
      Slot 3 CSU Serial #08625445 Model TEB HWVersion 4.70
      Framing is ESF, Line Code is B8ZS, Clock Source is Internal.
      Data in current interval (5 seconds elapsed):
         0 Line Code Violations, 0 Path Code Violations
         0 Slip Secs, 0 Fr Loss Secs, 0 Line Err Secs, 0 Degraded Mins
         0 Errored Secs, 0 Bursty Err Secs, 0 Severely Err Secs, 0 Unavail Secs
    wss-3810a#

    3810-C
    wss-3810c# show network-clocks 
    Priority 1 clock source(desired config): T1 0
    Priority 1 clock source(run-time config): T1 0
    Clock switch delay: 10
    Clock restore delay: 10
    T1 0 is clocking system bus for 3672 seconds.
    Run Priority Queue:  controller0,
     
    wss-3810c# show cont t1 0
    T1 0 is up.
      No alarms detected.
      Slot 3 CSU Serial #06706054 Model TEB HWVersion 4.70
      Framing is ESF, Line Code is B8ZS, Clock Source is Line.
      Data in current interval (40 seconds elapsed):
         0 Line Code Violations, 0 Path Code Violations
         0 Slip Secs, 0 Fr Loss Secs, 0 Line Err Secs, 0 Degraded Mins
         0 Errored Secs, 0 Bursty Err Secs, 0 Severely Err Secs, 0 Unavail Secs
    wss-3810c#

  4. MC3810 Configurations

    Here's a quick look at the new configurations for the MC3810 units. Only the 3810A experienced any configuration changes.

    3810-A
    wss-3810a# wr t
    Building configuration...
     
    Current configuration:
    !
    version 11.3
    !
    hostname wss-3810a
    !
    network-clock base-rate 64k
    network-clock-select 1 system(SCB)
    !
    controller T1 0
     framing esf
     clock source internal
     linecode b8zs
     channel-group 0 timeslots 1-24 speed 64
    !
    controller T1 1
     framing esf
     clock source loop-timed
     linecode b8zs
    !

    3820-C
    wss-3810c# wr t
    Building configuration...
     
    Current configuration:
    !
    version 11.3
    !
    hostname wss-3810c
    !
    network-clock base-rate 64k
    network-clock-select 1 T1 0
    !
    controller T1 0
     framing esf
     linecode b8zs
     channel-group 0 timeslots 1-24 speed 64
    !
    controller T1 1
     framing esf
     clock source loop-timed
     linecode b8zs
    !

Adaptive Clocking

Adaptive clocking is usually the choice when you cannot tie the CPE devices and the network elements to the same clock (otherwise, you would be using synchronous clocking). It's also used when you cannot tie the CPE devices to one clock and the network elements to another clock (otherwise, you would be using SRTS clocking). That leaves you with the option of tying one CPE to one clock, the other CPE to another clock, and the network elements to a third clock. This is not an ideal situation with a leased line, and using circuit emulation does not automatically make things better. Adaptive clocking merely adjusts the Transmit clocking on the CESM T1/E1 interface based on buffer size: when the buffer gets full, speed up the clock, when the buffer empties, slow the clock down.

In this example, we basically extend the SRTS configuration by changing the channel clocking configuration to adaptive and changing the clocking on 3810-C so that both MC3810 units are clocking using their internal clock.

UDT-Adaptive.gif

  1. CESM—Modify Channels for Adaptive Clocking

    MGX-B
    wss-mgxb.1.10.CESM.a > cnfchan 121 1000 1000 0 3 1 1
     
    wss-mgxc.1.10.CESM.a > cnfchan 122 1000 1000 0 3 1 1
    

  2. MC3810—Change Clock Source on 3810-C

    3810-C
    wss-3810c# conf t
    Enter configuration commands, one per line.  End with CNTL/Z.
    wss-3810c(config)# no network-clock-select 1 T1 0
    wss-3810c(config)# network-clock-select 1 system(SCB) 
    wss-3810c(config)#
    %MC3810_DSX1-5-MC3810_NOTICE: system(SCB) clocking PCM Bus
    %MC3810_DSX1-5-MC3810_NOTICE: system(SCB) clocking PCM Bus
     
    wss-3810c(config-controller)# cont t1 0
    wss-3810c(config-controller)# clock source internal
    wss-3810c(config-controller)# ^Z
    wss-3810c#
    %SYS-5-CONFIG_I: Configured from console by console
    wss-3810c#

  3. MC3810—Verify Clocking

    As you can see in the syntax of this configuration step, things are not as clean as with the other two clock modes. The lines are up, but slips and errored seconds abound. It is also interesting to look at the reported cell rate on the PVC configured on the BPX nodes. The internal clocks on the MC3810 units are obviously running a bit fast because the cell rate has increased. (Note: increasing the PVC cell rate for the connection did not eliminate the slip/errored seconds problem.)

    3810-A
    wss-3810a# show network-clocks
    Priority 1 clock source(desired config): system(SCB)
    Priority 1 clock source(run-time config): system(SCB)
    Clock switch delay: 10
    Clock restore delay: 10
    system(SCB) is clocking system bus for 32 seconds.
    Run Priority Queue:  system(SCB),
    
    wss-3810a# show cont t1 0
    T1 0 is up.
      No alarms detected.
      Slot 3 CSU Serial #08625445 Model TEB HWVersion 4.70
      Framing is ESF, Line Code is B8ZS, Clock Source is Internal.
      Data in current interval (74 seconds elapsed):
         0 Line Code Violations, 945 Path Code Violations
         23 Slip Secs, 0 Fr Loss Secs, 0 Line Err Secs, 1 Degraded Mins
         74 Errored Secs, 74 Bursty Err Secs, 0 Severely Err Secs, 0 Unavail Secs
    wss-3810a#

    3810-C
    wss-3810c# show network-clocks
    Priority 1 clock source(desired config): system(SCB)
    Priority 1 clock source(run-time config): system(SCB)
    Clock switch delay: 10
    Clock restore delay: 10
    system(SCB) is clocking system bus for 614 seconds.
    Run Priority Queue:  system(SCB),
    
    wss-3810c# show cont t1 0
    T1 0 is up.
      No alarms detected.
      Slot 3 CSU Serial #06706054 Model TEB HWVersion 4.70
      Framing is ESF, Line Code is B8ZS, Clock Source is Internal.
      Data in current interval (102 seconds elapsed):
         0 Line Code Violations, 1326 Path Code Violations
         66 Slip Secs, 0 Fr Loss Secs, 0 Line Err Secs, 1 Degraded Mins
         94 Errored Secs, 94 Bursty Err Secs, 8 Severely Err Secs, 0 Unavail Secs
    wss-3810c#

    BPX-B
    wss-bpxb       TN    StrataCom       BPX 8600  9.1.04    Nov. 16 1998 13:17 EST 
    
    Channel Statistics for 3.1.10.121  Cleared: Nov. 16 1998 13:17  (/)  Snapshot
    PCR: 4107/4107 cps      Collection Time: 0 day(s) 00:00:32      Corrupted: NO
       Traffic      Cells      CLP      Avg CPS   %util  Chan Stat Addr: 31132770
    From Port   :    131711          0     4108     100
    To Network  :    131711    ---         4108     100
    From Network:    131712          0     4108     100
    To Port     :    131712          0     4108     100
                                                                                    
    Rx Frames Rcv :         0  NonCmplnt Dscd:         0  Rx Q Depth    :         0
    Tx Q Depth    :         0  Rx CLP0       :    131711  Rx Nw CLP0    :    131712
    Igr VSVD ACR  :         0  Egr VSVD ACR  :         0  Tx Clp 0      :    131712
    Rx Clp 0+1    :    131711  Tx Clp 0 Dscd :         0  Tx Clp 1 Dscd :         0
    Tx Clp0+1 Dscd:         0
    
    Last Command: dspchstats 3.1.10.121 1
    

  4. CESM—Monitor Connection Statistics

    In the output shown in this step, notice that the CESM card thinks that everything is functioning correctly. Granted, the syntax below was copied for this document within 60 seconds of clearing the counters, but there are no lost cells or other anomalies. This implies is that the AAL1 cells are getting between the CESM cards, but are having problems staying in tune with the tight MC3810 clocking requirements.

    MGX-B
    wss-mgxb.1.10.CESM.a > clrchancnts
    wss-mgxb.1.10.CESM.a > clrsarcnts
    
    wss-mgxb.1.10.CESM.a > dspchancnt 121
    ChanNum:                   121
    Chan State:                okay
    Chan RCV ATM State:        Normal
    Chan XMT ATM State:        Normal
    Cell Loss Status:          No Cell Loss
    Reassembled Cells:         292885
    Generated Cells:           292885
    Header Errors:             0
    Seqence Mismatches :       0
    Lost Cells:                0
    Channel Uptime (secs.)     20391
    Signalling Status          Offhook
    
    wss-mgxb.1.10.CESM.a > dspsarcnt 121
                              SarShelfNum:         1
                              SarSlotNum:          10
                              SarChanNum:          121
                                    Tx                      Rx
                              ---------------       ---------------
      Total Cells:            466696                466698
      Total CellsCLP:         0                     0
      Total CellsAIS:         0                     0
      Total CellsFERF:        0                     0
      Total CellsEnd2EndLpBk: 0                     0
      Total CellsSegmentLpBk: 0                     0
      RcvCellsDiscOAM:                              0

  5. MC3810 Configurations

    3810-A
    wss-3810a# wr t
    Building configuration...
    
    Current configuration:
    !
    version 11.3
    !
    hostname wss-3810a
    !
    network-clock base-rate 64k
    network-clock-select 1 system(SCB)
    !
    controller T1 0
     framing esf
     clock source internal
     linecode b8zs
     channel-group 0 timeslots 1-24 speed 64
    !
    controller T1 1
     framing esf
     clock source loop-timed
     linecode b8zs
    !

    3810-C
    wss-3810c# wr t
    Building configuration...
    
    Current configuration:
    !
    version 11.3
    !
    hostname wss-3810c
    !
    network-clock base-rate 64k
    network-clock-select 1 system(SCB)
    !
    controller T1 0
     framing esf
     clock source internal
     linecode b8zs
     channel-group 0 timeslots 1-24 speed 64
    !
    controller T1 1
     framing esf
     clock source loop-timed
     linecode b8zs

Framing on VC Disconnect

The framingOnVcDisconnect port option is used when connecting legacy CPE to the CESM-8. This option is very much like the unstructured port. The only difference between framingOnVcDisconnect and unstructured port is when there is a network side cell loss. In the case of an unstructured port, conditional data is sent on the line. In the case of framingOnVcDisconnect, the line data that is received from the CPE is looped back to the CPE, so the CPE will not loose framing.

  1. CESM—Reconfigure Port for framingOnVcDisconnect

    Unfortunately, you cannot simply redefine the port type at any time. You have to remove the channel associated with the port first, reconfigure the port, readd the channel, and adjust channel configuration. These configurations show the steps:

    MGX-B
    wss-mgxb.1.10.CESM.a > delchan 121
    wss-mgxb.1.10.CESM.a > delport 21
    wss-mgxb.1.10.CESM.a > addport 21 2 1 24 3
    wss-mgxb.1.10.CESM.a > addchan 121 21 1 0 255 15
    wss-mgxb.1.10.CESM.a > cnfchan 121 1000 1000 0 2 1 1
     
    wss-mgxb.1.10.CESM.a > dspport 21
      SlotNum:                      10
      PortLineNum:                  2
      PortNum:                      21
      PortRowStatus:                Add
      PortNumOfSlots:               24
      PortDs0ConfigBitMap(1stDS0):  0xffffff(1)
      PortSpeed:                    1544kbps
      PortType:                     framingOnVcDisconnect
      PortState:                    Active
    
    ss-mgxb.1.10.CESM.a > dspchans
        Channel     ChanNum   Status   CDV   MaxBufSize   CLIP    CBRservice
      ------------  -------   ------  -----  ----------  ------  ------------
      10.2.21.121     121      Mod     1000      384      1000   unstructured
     
      Number of channels:    1

    MGX-C
    wss-mgxc.1.10.CESM.a > delchan 122
    wss-mgxc.1.10.CESM.a > delport 22
    wss-mgxc.1.10.CESM.a > addport 22 2 1 24 3
    wss-mgxc.1.10.CESM.a > addchan 122 22 1 0 255 15
    wss-mgxc.1.10.CESM.a > cnfchan 122 1000 1000 0 2 1 1
     
    wss-mgxc.1.10.CESM.a > dspport 22
      SlotNum:                      10
      PortLineNum:                  2
      PortNum:                      22
      PortRowStatus:                Add
      PortNumOfSlots:               24
      PortDs0ConfigBitMap(1stDS0):  0xffffff(1)
      PortSpeed:                    1544kbps
      PortType:                     framingOnVcDisconnect
      PortState:                                      Active

  2. MS3810—CPE Behavior with framingOnVcDisconnect

    With the PVC down between BPX-B and BPX-C, we see that the T1 controllers on the 3810 units do not go down and that the HDLC keepalives are looped back to the MC3810 units. However, the CESM card still shows cell loss and an alarm state.

    BPX-B
    wss-bpxb       TN    StrataCom       BPX 8600  9.1.04    Nov. 13 1998 15:51 EST 
     
     Local           Remote      Remote                             Route
     Channel         NodeName    Channel         State  Type        Avoid COS O
     3.1.10.121      wss-bpxc    10.1.10.122     Down   cbr                0  L
     
    Last Command: dncon 3.1.10.121
    

    3810-A
    wss-3810a# deb serial interface
    Serial2: HDLC myseq 1, mineseen 1*, yourseen 16, line up 
    Serial2: HDLC myseq 2, mineseen 2*, yourseen 17, line up 
    Serial2: HDLC myseq 3, mineseen 3*, yourseen 18, line up 
    Serial2: HDLC myseq 4, mineseen 4*, yourseen 19, line up 
    Serial2: HDLC myseq 5, mineseen 5*, yourseen 20, line up 
    Serial2: HDLC myseq 6, mineseen 6*, yourseen 21, line up 
    Serial2: HDLC myseq 7, mineseen 7*, yourseen 22, line up 
    
    /** Connection downed at this point **/
    
    Serial2: HDLC myseq 8, mineseen 8*, yourseen 23, line up 
    Serial2: HDLC myseq 9, mineseen 9*, yourseen 24, line up 
    Serial2 - Keepalive time mismatch - should be 10 secs, is 6
    Serial2: HDLC myseq 10, mineseen 24*, yourseen 10, line up (looped)
    Serial2: HDLC myseq 11, mineseen 10*, yourseen 11, line up (looped)
    
    wss-mgxb.1.10.CESM.a > clrchancnts
    wss-mgxb.1.10.CESM.a > clrsarcnts
    wss-mgxb.1.10.CESM.a > dspchancnt 121
    
    ChanNum:                   121
    Chan State:                alarm
    Chan RCV ATM State:        Normal
    Chan XMT ATM State:        Normal
    Cell Loss Status:          Cell Loss
    Reassembled Cells:         0
    Generated Cells:           38019
    Header Errors:             0
    Seqence Mismatches :       0
    Lost Cells:                0
    Channel Uptime (secs.)     356
    Signalling Status          Offhook
     
    wss-mgxb.1.10.CESM.a > dspsarcnt 121
                              SarShelfNum:         1
                              SarSlotNum:          10
                              SarChanNum:          121
                                    Tx                      Rx
                              ---------------       ---------------
      Total Cells:            80725                 0
      Total CellsCLP:         0                     0
      Total CellsAIS:         0                     0
      Total CellsFERF:        0                     0
      Total CellsEnd2EndLpBk: 0                     0
      Total CellsSegmentLpBk: 0                     0
      RcvCellsDiscOAM:                              0

    3810-C
    wss-3810c# deb serial interface
    Serial2: HDLC myseq 16, mineseen 16*, yourseen 2, line up 
    Serial2: HDLC myseq 17, mineseen 17*, yourseen 3, line up 
    Serial2: HDLC myseq 18, mineseen 18*, yourseen 4, line up 
    Serial2: HDLC myseq 19, mineseen 19*, yourseen 5, line up 
    Serial2: HDLC myseq 20, mineseen 20*, yourseen 6, line up 
    Serial2: HDLC myseq 21, mineseen 21*, yourseen 7, line up 
    Serial2: HDLC myseq 22, mineseen 22*, yourseen 8, line up 
    
    /** Connection downed at this point **/
    
    Serial2: HDLC myseq 23, mineseen 23*, yourseen 9, line up 
    Serial2: HDLC myseq 24, mineseen 23, yourseen 9, line up 
    Serial2 - Keepalive time mismatch - should be 10 secs, is 13
    Serial2: HDLC myseq 25, mineseen 9*, yourseen 25, line up (looped)
    Serial2: HDLC myseq 26, mineseen 25*, yourseen 26, line up (looped)

  3. MC3810—CPE Behavior without framingOnVcDisconnect

    The output for this configuration step demonstrates what would have happened if we downed the PVC when the ports were configured as unstructured:

    3810-A
    wss-3810a# deb serial int
    Serial network interface debugging is on
    wss-3810a#
    
    Serial2: HDLC myseq 282, mineseen 282*, yourseen 283, line up 
    Serial2: HDLC myseq 283, mineseen 283*, yourseen 284, line up 
    
    /** Connection downed at this point **/
    
    %CONTROLLER-5-UPDOWN: Controller T1 0, changed state to down
    %LINEPROTO-5-UPDOWN: Line protocol on Interface Serial2, changed state to down
    %LINK-3-UPDOWN: Interface Serial2, changed state to down
    
    wss-mgxb.1.10.CESM.a > clrsarcnts
    wss-mgxb.1.10.CESM.a > clrchancnts
    wss-mgxb.1.10.CESM.a > dspchancnt 121
    ChanNum:                   121
    Chan State:                alarm
    Chan RCV ATM State:        Normal
    Chan XMT ATM State:        Normal
    Cell Loss Status:          Cell Loss
    Reassembled Cells:         0
    Generated Cells:           25782
    Header Errors:             0
    Seqence Mismatches :       0
    Lost Cells:                0
    Channel Uptime (secs.)     3221
    Signalling Status          Offhook
     
    wss-mgxb.1.10.CESM.a > dspsarcnt 121
                              SarShelfNum:         1
                              SarSlotNum:          10
                              SarChanNum:          121
                                    Tx                      Rx
                              ---------------       ---------------
      Total Cells:            70951                 0
      Total CellsCLP:         0                     0
      Total CellsAIS:         0                     0
      Total CellsFERF:        0                     0
      Total CellsEnd2EndLpBk: 0                     0
      Total CellsSegmentLpBk: 0                     0
      RcvCellsDiscOAM:                              0

    3810-C
    wss-3810c# deb serial int
    Serial network interface debugging is on
    wss-3810c#
    Serial2: HDLC myseq 283, mineseen 283*, yourseen 283, line up 
    %CONTROLLER-5-UPDOWN: Controller T1 0, changed state to down
    
    /** Connection downed at this point **/
                              
    %LINEPROTO-5-UPDOWN: Line protocol on Interface Serial2, changed state to down
    %LINK-3-UPDOWN: Interface Serial2, changed state to down

Command List

This section lists the commands, with available options and values, used in the configuration examples throughout this document.

addln line_num , where…

  • line_num can be a numeric value in the range from 1 to 8.

cnfln line_num line_code line_len clk_src [E1-signaling] , where…

  • line_num can be a numeric value in the range from 1 to 8.

  • line_code can be:

    • 2 = B8ZS (T1)

    • 3 = HDB3 (E1)

    • 4 = AMI (T1/E1)

  • line_len (line length) can be:

    • 8 = E1 with SMB line module

    • 9 = E1 with RJ48 line module

    • 10 = T1 0 to 131 ft. line build out

    • 11 = T1 131 to 262 ft.

    • 12 = T1 262 to 393 ft.

    • 13 = T1 393 to 524 ft.

    • 14 = T1 524 to 655 ft.

    • 15 = T1 > 655 ft.

  • clk_src (clock source) can be:

    • 1 = Loop clock; the transmit clock on the interface is locked to the receive clock from the attached device.

    • 2 = Local clock; the CESM-8 cards uses clock derived from the backplane to drive the transmit clock.

  • E1-signaling can be:

    • CAS = Channel Associated Signaling; signaling information is contained in timeslot 16 and framing is carried in timeslot 0.

    • CAS_CRC = CAS with Cyclic Redundancy Check (CRC).

    • CCS = Common Channel Signaling; signaling information is not tied to a particular timeslot. Framing is still carried in the first timeslot.

    • CCS_CRC = CCS with CRC.

    • CLEAR = No attempt is made to identify framing or signaling on the incoming stream. The entire data stream is considered data.

addport port_num line_num begin_slot num_slot port_type , where…

  • port_num can be:

    • In the range from 1 to 192 = T1 (8 lines * 24 DS0s/line)

    • In the range from 1 to 248 = E1 (8 lines * 31 DS0s / line)

  • line_num can be a numeric value from 1 to 8.

  • begin_slot is the beginning time slot in line to start port.

  • num_slot is the number of DS0 time slots assigned to the port.

  • port_type can be:

    • 1 = Structured

      For T1, you can set up a structured port type for bandwidths ranging from 1 to 24 DS0s.

      For E1, structured ports can not include the framing timeslot (CCS or CAS), or the signaling timeslot (CAS).

    • 2 = Unstructured

      For T1, unstructured port = 24 DS0s.

      For E1, unstructured port can only be configured when the E1 signaling is set to CLEAR.

    • 3 = framingOnVcDisconnect

      This port type is basically the same as unstructured with one key difference—when an unstructured port experiences a network-side cell loss, the CESM-8 transmits conditional data down the line. With framingOnVcDisconnect, cell loss from the network side results in the CESM-8 looping back data received from the CPE back out the port so that the CPE does not lose framing. The same restrictions on DS0 count and signaling type present for an unstructured port apply here.

addchan chan_num port_num CesCas partial_fill cond_data cond_signaling , where…

  • chan_num can be a numeric value in the range from 32 to 279.

  • port_num can be:

    • In the range from 1 to 192 = T1 (8 lines * 24 DS0s/line)

    • In the range from 1 to 248 = E1 (8 lines * 31 DS0s / line)

  • CesCas can be:

    • 1 = Basic; the CES interworking function does not recognize signaling information for special transport across the network.

    • 2 = e1Cas; recover E1 Channel Associated Signaling (CAS) for transport.

    • 3 = ds1SfCas; recover T1 Channel Associated Signaling from a SuperFrame structure (ABAB).

    • 4 = ds1EsfCas; recover T1 CAS from an Extended SuperFrame structure (ABCD).

  • partial_fill can be 0 (zero) or a value from 20 to 47:

    • 0 or 47 = Fully filled

    • In the range from 20 to 47 = E1 structured

    • In the range from 25 to 47 = T1 structured

    • In the range from 33 to 47 = T1/E1 unstructured

  • cond_data can be:

    • 0 to 255 = Structured Data Transport (SDT)

    • 255 = Unstructured Data Transport (UDT)

  • cond_signaling is a decimal representation of the the 4-bit ABCD bit pattern, in the range from 0 to 15, where…

    • 0 = 0000 binary

    • 1 decimal = 0001 binary

    • 8 decimal = 1000 binary

    • 15 decimal = 1111 binary

cnfchan chan_num CDV CLIP bufsize clockmode IdleDetEnable ExtIStrig , where…

  • chan_num can be a numeric value in the range from 32 to 279.

  • CDV (Cell Delay Variation) can be:

    • In the range from 1000 to 24000 micro seconds, for T1 (in increments of 125).

    • In the range from 1000 to32000 micro seconds, for E1 (in increments of 125).

  • CLIP (Cell Loss Integration Period) can be a value in the range from 1000 to 65535 milliseconds.

  • bufsize (the egress buffer size, in bytes) can be:

    • 0 = Autocompute buffer size (must be large enough to hold 8 SAR-PDUs).

    • Minimum buffer size = 384 bytes (8 cell payloads to one complete seq. num cycle).

    • Maximum buffer size = 9216 for T1 structured; 16384 for others.

  • clockmode can be:

    • 1 = Synchronous (UDT/SDT)

    • 2 = SRTS (UDT)

    • 3 = Adaptive (UDT)

  • IdleDetEnable can be:

    • 1 = Disable

    • 2 = Enable

  • ExtIStrig can be:

    • 1 = Disable idle suppression

    • 2 = Enable idle suppression

Verify

There is currently no verification procedure available for this configuration.

Troubleshoot

There is currently no specific troubleshooting information available for this configuration.

Related Information

Updated: Apr 30, 2009
Document ID: 22236