Verifying an ISDN PRI Interface and Checking B-Channel Interface Statistics
Purpose
Verify that an ISDN B-channel interface is operating properly. For ISDN PRI, verify that a B-channel interface is configured correctly. (To display a list of B-channel interfaces, enter the show isdn calls command.)
Action
From the CLI, enter the show interfaces extensive command. Alternatively, from the J-Web interface select Monitor>Interfaces>bc-0/0/4:1.
Sample Output
user@host> show interfaces bc-0/0/4:1
extensivePhysical interface: bc-0/0/4:1, Administratively down, Physical link is Up
Interface index: 145, SNMP ifIndex: 75, Generation: 26
Type: Serial, Link-level type: Multilink-PPP, MTU: 1510, Clocking: Internal,
Speed: 64kbps,
Parent: br-0/0/4 Interface index 143
Device flags : Present Running
Interface flags: Admin-Test SNMP-Traps 16384
Link type : Full-Duplex
Link flags : None
Physical info : Unspecified
Hold-times : Up 0 ms, Down 0 ms
Current address: Unspecified, Hardware address: Unspecified
Alternate link address: Unspecified
CoS queues : 8 supported, 8 maximum usable queues
Last flapped : Never
Statistics last cleared: Never
Traffic statistics:
Input bytes : 5787 0 bps
Output bytes : 3816 0 bps
Input packets: 326 0 pps
Output packets: 264 0 pps
Input errors:
Errors: 0, Drops: 0, Framing errors: 0, Runts: 0, Giants: 0, Policed discards: 6,
Resource errors: 0
Output errors:
Carrier transitions: 0, Errors: 0, Drops: 0, MTU errors: 0, Resource errors: 0
Queue counters Queued packets Transmitted Packets Dropped packets
0 best-effort 314335 0 0
1 best-effort 0 0 0
2 best-effort 5 0 0
3 best-effort 5624 5624 0
Packet Forwarding Engine configuration:
Destination slot: 5, PLP byte: 1 (0x00)
CoS transmit queue Bandwidth Buffer Priority Limit
% bps % usec
0 best-effort 95 60800 95 0 low none
3 network-control 5 3200 5 0 low none
Logical interface bc-0/0/4:1.0 (Index 71) (SNMP ifIndex 61) (Generation 33)
Flags: Device Down Point-To-Point SNMP-Traps Encapsulation: PPP
Protocol mlppp, Multilink bundle: dl0.0, MTU: 1506, Generation: 18, Route table: 0
Meaning
The output shows a summary of B-channel interface information. Verify the following information:
- The physical interface is Enabled. If the interface
is shown as Disabled, do either of the following:
- In the CLI configuration editor, delete the disable statement at the [edit interfaces interface-name] level of the configuration hierarchy.
- In the J-Web configuration editor, clear the Disable check box on the Interfaces>interface-name page.
- The physical link is Up. A link state of Down indicates a problem with the interface module, interface port, or physical connection (link-layer errors).
- For ISDN BRI, the Parent interface is a br-pim/0/port interface—br-0/0/4 in this example. For ISDN PRI, the Parent interface is a channelized T1 or channelized E1 interface—ct1–pim/0/port or ce1–pim/0/port.
- The Last Flapped time is an expected value. The Last Flapped time indicates the last time the physical interface became unavailable and then available again. Unexpected flapping indicates possible link-layer errors.
- The traffic statistics reflect expected input and output rates. Verify that the number of inbound and outbound bytes and packets matches expected throughput for the physical interface. To clear the statistics and see only new changes, use the clear interfaces statistics interface-name command.
Related Topics
For a complete description of show interfaces (ISDN B-channel) output, see the JUNOS Interfaces Command Reference.