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ISDN Layer 2 status is looking weird, but calls are working fine.

Hi Guys,

I just ran a sh isdn status command on voice gateway & found that layer 2 status is looking weird, Is there anyone who knows, why is that ?

Here is the output:

cpp-vgw-1#sh isdn st

Global ISDN Switchtype = primary-4ess

%Q.931 is backhauled to CCM MANAGER 0x0003 on DSL 0. Layer 3 output may not apply

ISDN Serial1/0:15 interface

        dsl 0, interface ISDN Switchtype = primary-net5

        L2 Protocol = Q.921 0x0000  L3 Protocol(s) = CCM MANAGER 0x0003

    Layer 1 Status:

        ACTIVE

    Layer 2 Status:

        TEI = 0, Ces = 1, SAPI = 0, State = MULTIPLE_FRAME_ESTABLISHED

        TEI = 0, Ces = 1, SAPI = 63, State = TEI_ASSIGNED

    Layer 3 Status:

        0 Active La

    Active dsl 0 CCBs = 0

    The Free Channel Mask:  0xFFFF7FFF

    Number of L2 Discards = 0, L2 Session ID = 91

Thanks: Mohit Grover MCP, MCSE, MCITP CCIE Voice # 35961 BCA (Network Communications) MCA (Network Communications)
9 REPLIES
Green

ISDN Layer 2 status is looking weird, but calls are working fine

Mohit,

This looks like an issue with link establisment.

Your Call Manager gateway endpoint and router should have the same isdn switch type

and importantly agree with the switch type of the service provider.

Regards,
Alex.
Please rate useful posts.

Regards, Alex. Please rate useful posts.

ISDN Layer 2 status is looking weird, but calls are working fine

Hi Alex,

Yes configuration is just like that.

Thanks: Mohit Grover MCP, MCSE, MCITP CCIE Voice # 35961 BCA (Network Communications) MCA (Network Communications)

ISDN Layer 2 status is looking weird, but calls are working fine

Hi Mohit,

This output you can see during TEI negotiation.

Did you modify any of the configurtaion before layer 2 status comes into active state (i.e. Multiframe established) ?

For confirmation, execute debug q921 command and check if you are still receiving TEI state with SAPI other than 0.

If NO, then the possibility is that the router / gateway has kept the old status in it's pool and appended the new status.

Try to clear counters and reset the link to re-establish the link status and monitor it.

Regards, Nishant Savalia
VIP Purple

ISDN Layer 2 status is looking weird, but calls are working fine

Hi Mohit,

Can u share the config/version/inventory of router?

what is CUCM version u are using?

regds,

aman

ISDN Layer 2 status is looking weird, but calls are working fine

Hi Aman, below is the sh hardware & version output, & CCM version is 7.1.5.

2-rpi-vgw-2#sh hard

Cisco IOS Software, 3800 Software (C3845-ADVENTERPRISEK9-M), Version 12.4(24)T3, RELEASE SOFTWARE (fc2)

Technical Support: http://www.cisco.com/techsupport

Copyright (c) 1986-2010 by Cisco Systems, Inc.

Compiled Tue 23-Mar-10 11:22 by prod_rel_team

ROM: System Bootstrap, Version 12.4(13r)T, RELEASE SOFTWARE (fc1)

2-rpi-vgw-2 uptime is 45 weeks, 5 days, 21 hours, 13 minutes

System returned to ROM by power-on

System restarted at 12:10:21 CST Fri Aug 17 2012

System image file is "flash:c3845-adventerprisek9-mz.124-24.T3.bin"

This product contains cryptographic features and is subject to United

States and local country laws governing import, export, transfer and

use. Delivery of Cisco cryptographic products does not imply

third-party authority to import, export, distribute or use encryption.

Importers, exporters, distributors and users are responsible for

compliance with U.S. and local country laws. By using this product you

agree to comply with applicable laws and regulations. If you are unable

to comply with U.S. and local laws, return this product immediately.

A summary of U.S. laws governing Cisco cryptographic products may be found at:

http://www.cisco.com/wwl/export/crypto/tool/stqrg.html

If you require further assistance please contact us by sending email to

export@cisco.com.

Cisco 3845 (revision 1.0) with 746495K/39936K bytes of memory.

Processor board ID FTX1213A1CR

2 Gigabit Ethernet interfaces

124 Serial interfaces

6 Channelized/Clear E1/PRI ports

2 Channelized (E1 or T1)/PRI ports

1 Virtual Private Network (VPN) Module

DRAM configuration is 64 bits wide with parity enabled.

479K bytes of NVRAM.

125440K bytes of ATA System CompactFlash (Read/Write)

Configuration register is 0x2102

____________________________________________________________

2-rpi-vgw-2# sh version

Cisco IOS Software, 3800 Software (C3845-ADVENTERPRISEK9-M), Version 12.4(24)T3, RELEASE SOFTWARE (fc2)

Technical Support: http://www.cisco.com/techsupport

Copyright (c) 1986-2010 by Cisco Systems, Inc.

Compiled Tue 23-Mar-10 11:22 by prod_rel_team

ROM: System Bootstrap, Version 12.4(13r)T, RELEASE SOFTWARE (fc1)

2-rpi-vgw-2 uptime is 45 weeks, 5 days, 21 hours, 13 minutes

System returned to ROM by power-on

System restarted at 12:10:21 CST Fri Aug 17 2012

System image file is "flash:c3845-adventerprisek9-mz.124-24.T3.bin"

This product contains cryptographic features and is subject to United

States and local country laws governing import, export, transfer and

use. Delivery of Cisco cryptographic products does not imply

third-party authority to import, export, distribute or use encryption.

Importers, exporters, distributors and users are responsible for

compliance with U.S. and local country laws. By using this product you

agree to comply with applicable laws and regulations. If you are unable

to comply with U.S. and local laws, return this product immediately.

A summary of U.S. laws governing Cisco cryptographic products may be found at:

http://www.cisco.com/wwl/export/crypto/tool/stqrg.html

If you require further assistance please contact us by sending email to

export@cisco.com.

Cisco 3845 (revision 1.0) with 746495K/39936K bytes of memory.

Processor board ID FTX1213A1CR

2 Gigabit Ethernet interfaces

124 Serial interfaces

6 Channelized/Clear E1/PRI ports

2 Channelized (E1 or T1)/PRI ports

1 Virtual Private Network (VPN) Module

DRAM configuration is 64 bits wide with parity enabled.

479K bytes of NVRAM.

125440K bytes of ATA System CompactFlash (Read/Write)

Configuration register is 0x2102

FYI - I've checked the configuration thrice, but it is looking good, prior to this issue this circuit had been facing issues with Service Provider which is Telefonica.

Thanks: Mohit Grover MCP, MCSE, MCITP CCIE Voice # 35961 BCA (Network Communications) MCA (Network Communications)

ISDN Layer 2 status is looking weird, but calls are working fine

Hi Nishant,

Nope, I did not make any changes myself, & configuration is looking good.

Q921 messages are looking good, & calls are working fine, there is no impact.

I've aleady raised a ticket with SP on this & waiting for their response. (It might be a SP issue)

Thanks: Mohit Grover MCP, MCSE, MCITP CCIE Voice # 35961 BCA (Network Communications) MCA (Network Communications)

ISDN Layer 2 status is looking weird, but calls are working fine

Might be an issue of SP.

Check logs whether you have received any alarm regarding link failure or any kind of fluctuation, because at present as you said there is no any issue in Q921 messages.

Regards, Nishant Savalia

ISDN Layer 2 status is looking weird, but calls are working fine

It has been resolved auto., it was a SP issue but as usual they are still not accepting it. LOLzzz

Thanks: Mohit Grover MCP, MCSE, MCITP CCIE Voice # 35961 BCA (Network Communications) MCA (Network Communications)

ISDN Layer 2 status is looking weird, but calls are working fine

I saw that a couple of times, I found some situations where is a "Cosmetic" bug, usually a reload fix it... Not sure if this is the case, but I'm glad it is resolved now.

--
Jorge Armijo

Please remember to rate helpful responses and identify helpful or correct answers.

-- Jorge Armijo Please remember to rate helpful responses and identify helpful or correct answers.
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