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Cisco ASR 900 Router Series Configuration Guide, Cisco IOS XE Fuji 16.7.x

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Cisco ASR 900 Router Series Configuration Guide, Cisco IOS XE Fuji 16.7.x

Chapter Title

Configuring Serial Interfaces

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Updated:
April 11, 2018

Chapter: Configuring Serial Interfaces

Configuring Serial Interfaces

This chapter configures the serial interface module (PN: A900-IMASER14A/S) Async R232 serial data using Transparent Pseudowire (PW) over MPLS network on the Cisco ASR 900 Series Router. It includes the following sections:

For information about managing your system images and configuration files, refer to the Cisco IOS Configuration Fundamentals Configuration Guide and Cisco IOS Configuration Fundamentals Command Reference publications.

For more information about the commands used in this chapter, refer to the Cisco IOS Command Reference publication for your Cisco IOS software release.

Information About Serial Interface Module

The Cisco ASR 903 Series Router Serial interface module supports pseudowire types that utilize Async RS232 traffic over MPLS. The Serial IM interfaces monitor and detect cable connections, cable types and also monitors modem control signals periodically.

Figure 1. Pseudowire Transport for Serial Interface

The A900-IMASER14A/S interface provides a direct connection between the Cisco ASR 903 router and external networks.


Note
We recommend that you use a smart serial or 4-port octopus cable to connect the A900-IMASER14A/S with the external network.

Restrictions


Note

Serial interfaces are not supported on the ASR 900 RSP3 Module.

This section describes the port restrictions for Serial interface module:

  • Ports 0-7 are Async ports on the 68-pin connector

  • Ports 8-13 are Sync or Async on the 12-in-1 connector


Note

Sync is not supported in Cisco IOS XE Release 3.14S. Sync ports cannot be configured in Cisco IOS XE Release 3.14S.

  • Maximum speed on all ports is 236Kbps.

This section describes the software limitations that apply when configuring the Serial interface module:

  • The router can only be configured as data circuit-terminating equipment (DCE).

  • Configuration of pseudowire between local and remote PE with different speed on Sync and Async ports is not supported.

  • Sub-rate (below DS0 bandwidth) Async (R232) data over MPLS MPLS using T1/E1 CESoP is not supported.

  • Pseudowire ping is not supported for the pseusdowire configured on the serial interface module.

  • Only two serial interface modules can come up on the router in release prior to Cisco IOS XE Release 3.14. Starting with Cisco IOS XE Release 3.14, all 6 bays on the router are available for insertion of interface modules simultaneously.

  • Only Trans encapsulation is supported in Cisco IOS XE Release 3.14S.

  • If you installed a new A900-IMASER14A/S or if you want to change the configuration of an existing interface, you must enter configuration mode to configure the new interfaces. If you replaced an A900-IMASER14A/S that was previously configured, the system recognizes the new interfaces and brings each of them up in their existing configuration.

  • Pseudowire ping is not supported for cross-connect configured on ASR900-IMA14A/S interface module.

How to Configure Serial Interface

Required Configuration Tasks

Configuring the Controller

To create the interfaces for the Serial interface module, complete these steps:

SUMMARY STEPS

    1.    configure terminal

    2.    controller serial slot/subslot/port

    3.    physical-layer async

    4.    exit


DETAILED STEPS
     Command or ActionPurpose
    Step 1configure terminal


    Example:
    Router# configure terminal
     

    Enters global configuration mode.

     
    Step 2controller serial slot/subslot/port


    Example:
    Router(config)# controller serial 0/4/1
     

    Selects the controller to configure and enters controller configuration mode.

    • slot/subslot/port—Specifies the location of the interface.
    Note    The slot number is always 0.
     
    Step 3physical-layer async


    Example:
    Router(config-controller)# physical-layer async
     

    Configures the serial interface in async mode.

    • async—Specifies async interface.
     
    Step 4exit


    Example:
    Router(config)# exit
     

    Exits configuration mode and returns to the EXEC command interpreter prompt.

     
    Example: Controller Configuration
    Router# configure terminal
Router(config)# controller 
0/4/1
Router(config-controller)# physical-layer async
Router(config)# exit

    Optional Configurations

    Configuring Layer 1 on Async Interface

    The RS232 which is enabled by default on the async interface, supports RS232 DCE cable with the DB-25 connector. The Cisco smart serial cable with the DB-25 connector supports RS232 and RS485. The RJ45 cable type supports only RS485.

    SUMMARY STEPS

      1.    configure terminal

      2.    line slot/bay/port

      3.    databits {5 | 6 | 7 | 8}

      4.    stopbits {1 | 1.5 | 2}

      5.    speed speed-value

      6.    flowcontrol {none | software [lock | in | out] | hardware [in | out]

      7.    parity {even | mark | none | odd | space}

      8.    exit


    DETAILED STEPS
       Command or ActionPurpose
      Step 1configure terminal


      Example:
      Router# configure terminal
       

      Enters global configuration mode.

       
      Step 2line slot/bay/port


      Example:
      Router(config)# line 0/4/1
       

      Select the controller to configure and enters serial interface configuration mode.

      • slot/subslot/port—Specifies the location of the interface.
       
      Step 3databits {5 | 6 | 7 | 8}

      Example:
      Router(config-line)# databits 8


      Example:
      
 
            		 

      
Sets the databit configuration. The default is 8.
      

 
      
      

      Step 4stopbits {1 | 1.5 | 2}
       

      Example:
      Router(config-line)# stopbits 2
      
 
            		 

      
Sets the stopbit configuration. The default is 2.
      

 
      
      

      Step 5speed speed-value
       

      Example:
      Router(config-line)# speed 9600
      
 
            		 

      
Specifies the serial interface speed. The valid range is form 300 to 230400. The default is 9600.
      

 
      
      

      Step 6flowcontrol {none | software [lock | in | out] | hardware [in | out]
       

      Example:
      Router(config-line)# flowcontrol none
      
 
            		 

      
Sets the flowcontrol.
      


      • none
        • 

      • software
        • 

      • hardware
        • 

      

 
      
      

      Step 7parity {even | mark | none | odd | space} 

      Example:
      Router(config-line)# parity none
      
 
            		 

      
Sets the parity.
      

 
      
      

      Step 8exit
       

      Example:
      Router(config)# exit
      
 
            		 

      
Exits configuration mode and returns to the EXEC command interpreter prompt.
      

 
      
      

      

      

      Example: Async Layer 1 Parameters
      

      

      Router# configure terminal
Router(config)# line 0/4/1
Router(config-line)# databits 8
Router(config-line)# stopbits 2
Router(config-line)# speed 9600
Router(config-line)# flow-control none
Router(config-line)# parity none
Router(config-line)# exit
      


      

      

      

      

      Configuring a Channel Group
      

      SUMMARY STEPS
        1.   
      configure terminal
        

        2.   
      controller serial slot/bay/port
        

        3.   
      channel-group channel-group
        

        4.   
      exit
        


      DETAILED STEPS
         Command or ActionPurpose
        Step 1configure terminal
         

        Example:
        Router# configure terminal
        
 
              		 

        
Enters global configuration mode.
        

 
      
        

        Step 2controller serial slot/bay/port
         

        Example:
        Router(config)# controller serial 0/4/1
        
 
              		 

        
Configures the controller.
        


        slot/subslot/port—Specifies the location of the interface.
        

 
      
        

        Step 3channel-group channel-group
         

        Example:
        Router(config-controller)# channel-group 0
        
 
              		 

        
Configures the channel group with specified NxDS0 time slots.
        

 
      
        

        Step 4exit
         

        Example:
        Router(config-controller)# exit
        
 
              		 

        
Exits configuration mode and returns to the EXEC command interpreter prompt.
        

 
      
        

        

        

        Example: Channel Group
        

        

        Router# configure terminal
Router(config)# controller serial 0/4/1
Router(config-controller)# channel-group 0
Router(config-controller)# exit

        


        

        

        

        

        Configuring Encapsulation
        

        

        
When traffic crosses a WAN link, the connection needs a Layer 2 protocol to encapsulate traffic. 
        



        Note
        
L2TPv3 encapsulation is not
 supported on the Cisco ASR 900 Series router. Trans encapsulation is only supported in Cisco IOS XE Release 3.14S.
        


        
SUMMARY STEPS
          1.   
      configure terminal
          

          2.   
      interface serial slot/bay/port
          

          3.   
      encapsulation {ppp | trans | sdmc}
          

          4.   
      exit
          


        DETAILED STEPS
           Command or ActionPurpose
          Step 1configure terminal
           

          Example:
          Router# configure terminal
          
 
                		 

          
Enters global configuration mode.
          

 
      
          

          Step 2interface serial slot/bay/port
           

          Example:
          Router(config)# interface serial 0/4/1
          
 
                		 

          
Selects the interface to configure from global configuration mode.
          


          • slot/subslot/port—Specifies the location of the interface.
            • 

          

 
      
          

          Step 3encapsulation {ppp | trans | sdmc} 

          Example:
          Router(config-if)# encapsulation trans
          
 
                		 

          
Set the encapsulation method on the interface.
          


          • ppp—Described in RFC 1661, PPP encapsulates network layer protocol information over point-to-point links.
            • 

          • trans—Transparent encapsulation.
            • 

          


          Note   
                
              
Trans encapsulation is supported on the access side for serial interfaces which has cross connect configured.
          


          • sdmc—Switched Multimegabit Data Services (SDMC) for serial interface.
            • 

          

 
      
          

          Step 4exit
           

          Example:
          Router(config)# exit
          
 
                		 

          
Exits configuration mode and returns to the EXEC command interpreter prompt.
          

 
      
          

          

          

          

          Configuring Transparent Pseudowire (PW) Cross-Connect
          

          

          Example: Encapsulation
          

          

          Router# configure terminal
Router(config)# interface serial 0/
4/1
Router(config-if)# encapsulation trans
Router(config-if)# exit

          


          

          

          

          

          Configuring Transparent Pseudowire (PW) Cross-Connect
          

          

          
Transparent PW mode provides a facility to configure the speed between 300 bps to 230400 bps. 
          


          
SUMMARY STEPS
            1.   
      configure terminal
            

            2.   
      interface serial slot/bay/port
            

            3.   
      xconnect peer-router-id vcid encapsulation mpls
            

            4.   
      exit
            


          DETAILED STEPS
             Command or ActionPurpose
            Step 1configure terminal
             

            Example:
            Router# configure terminal
            
 
                  		 

            
Enters global configuration mode.
            

 
      
            

            Step 2interface serial slot/bay/port
             

            Example:
            Router(config)# interface serial 0/4/1
            
 
                  		 

            
Selects the interface to configure from global configuration mode.
            


            • slot/subslot/port—Specifies the location of the interface.
              • 

            

 
      
            

            Step 3xconnect peer-router-id vcid encapsulation mpls
             

            Example:
            Router(config-if)# xconnect 1.1.1.1 1001 encapsulation mpls
            
 
                  		 

            
Configures the VC to transport packets.
            

 
      
            

            Step 4exit
             

            Example:
            Router(config)# exit
            
 
                  		 

            
Exits configuration mode and returns to the EXEC command interpreter prompt.
            

 
      
            

            

            

            Example: Transparent Pseudowire on Cross Connect
            

            

            Router# configure terminal
Router(config)# interface serial 0/
4/1
Router(config-if)# xconnect 1.1.1.1 1001 encapsulation mpls
Router(config)# exit

            


            

            

            

            

            Configuring Invert Clock Signal
            

            SUMMARY STEPS
              1.   
      configure terminal
              

              2.   
      controller serial slot/bay/port
              

              3.   
      invert data
              

              4.   
      exit
              


            DETAILED STEPS
               Command or ActionPurpose
              Step 1configure terminal
               

              Example:
              Router# configure terminal
              
 
                    		 

              
Enters global configuration mode.
              

 
      
              

              Step 2controller serial slot/bay/port
               

              Example:
              Router(config)# controller serial 0/4/1
              
 
                    		 

              
Configures the controller.
              


              slot/subslot/port—Specifies the location of the interface.
              

 
      
              

              Step 3invert data
               

              Example:
              Router(config-controller)# invert data
              
 
                    		 

              
Configures the invert data clock signal.
              

 
      
              

              Step 4exit
               

              Example:
              Router(config)# exit
              
 
                    		 

              
Exits configuration mode and returns to the EXEC command interpreter prompt.
              

 
      
              

              

              

              Example: Invert Data on the Serial Interface
              

              

              
The following example shows invert data configuration on the serial interface.
              


              Router# configure terminal
Router(config)# controller serial 0/4/1
Router(config-controller)# invert data
Router(config-controller)# exit

              


              

              

              

              

              Saving the Configuration
              

              
To save your running configuration to nonvolatile random-access memory (NVRAM), use the following command in privileged EXEC configuration mode:
              


              

              
Command
              

              		


              
Purpose
              

              		

              
              

              

              copy running-config startup-config
              

              		


              
Writes the new configuration to NVRAM.
              

              		

              
              

              

              

              
For information about managing your system images and configuration files, refer to the Cisco IOS Configuration Fundamentals Configuration Guide
 
and Cisco IOS Configuration Fundamentals Command Reference 
publications.
              

              

              

              

              

              Verifying the Serial Interface Configuration
              

              
Use the following commands to verify the configuration the serial interface
              

              • show controllers serial slot/bay/port
                • 

              

              
Use the show controllers serial slot/bay/port command to display serial interface configuration on the router. 
              

              Router# show controllers serial 0/1/0
Serial0/1/0 - (A900-IMASER14A/S) is up
 Encapsulation : TRANSPARENT
 Cable type: RS-232 DCE
 mtu 1500, max_buffer_size 1524, max_pak_size 1524 enc 84
 loopback: Off,  crc: 16, invert_data: Off
 nrzi: Off, idle char: Flag
 dce_terminal_timing_enable: Off ignore_dtr: Off
 serial_clockrate: 128000bps, serial_clock_index: 17
 serial_restartdelay:30000,  serial_restartdelay_def:30000

              

              • show interfaces serial slot/bay/port 
                • 

              

              
Use the show interfaces serial slot/bay/port command to display serial interface packet status information, model control signal status information on the router. 
              

              Router# show interfaces serial 0/1/0
Serial0/1/0 is up, line protocol is up
  Hardware is A900-IMASER14A/S
  MTU 1500 bytes, BW 128 Kbit/sec, DLY 20000 usec,
     reliability 255/255, txload 1/255, rxload 1/255
  Encapsulation TRANSPARENT, loopback not set
  Keepalive not supported
  Last input never, output never, output hang never
  Last clearing of "show interface" counters 00:11:31
  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
     280058 packets input, 839125 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
     209844 packets output, 1048985 bytes, 0 underruns
     0 output errors, 0 collisions, 0 interface resets
     0 unknown protocol drops
     0 output buffer failures, 0 output buffers swapped out
     0 carrier transitions

              

              • 
show running-config interface serial
 slot/bay/port
                • 

              

              
Use the 
show running-config interface serial
 slot/bay/port command to display serial interface IP address information, keep alive and cross-connect status information on the router.
              

              Router# show running-config interface serial 0/1/0
Building configuration...
Current configuration : 107 bytes
!
interface Serial0/1/0
 no ip address
 encapsulation trans
 xconnect 1.1.1.1 1001 encapsulation mpls
End

              

              • show xconnet all
                • 

              

              
Use the 
show xconnect all to command to display all cross connect status on the router.
              

              Router# show xconnect all
Legend:    XC ST=Xconnect State  S1=Segment1 State  S2=Segment2 State
  UP=Up       DN=Down            AD=Admin Down      IA=Inactive
  SB=Standby  HS=Hot Standby     RV=Recovering      NH=No Hardware
XC ST  Segment 1                         S1 Segment 2                         S2
------+---------------------------------+--+---------------------------------+--
UP pri   ac Se0/1/0(HDLC)                UP mpls 1.1.1.1:1001                 UP

              

              

              

              Configuration Examples
              

              
This section includes the following configuration examples:
              

              

              Example: Encapsulation Configuration
              

              

              
The following example sets encapsulation for the controller and interface:
              


              

              PE1 CONFIG 
              

              controller SERIAL 0/1/0
 physical-layer async
 channel-group 0
interface Serial0/1/0
 no ip address
 encapsulation trans
 xconnect 2.2.2.2 1001 encapsulation mpls

              


              

              PE2 CONFIG
              

              controller SERIAL 0/2/0
 physical-layer async
 channel-group 0
interface Serial0/2/0
 no ip address
 encapsulation trans
 xconnect 1.1.1.1 1001 encapsulation mpls

              


              

              


              

              

              

              

              


              


               
 
    
              
    
              
        












              
    
              














              
  
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