VOICE GATEWAY TROUBLESHOOTING

[SOLID]

Hello All, One of my customers recently reported their inability to make outbound calls. The ISP has been contacted, and they have been insisting there's a loopback on the router, but I have logged on to the router and there is no loopback.

[Georg Pauwen]

Hello,

is this your edge device connected to your provider ? You are getting a remote alarm; unless you have changed your configuration, the problem is at the ISP end (more evidence of this are the line code violations).

You could try and toggle the Framing (CRC4) and Line Code is (HDB3) parameters in your controller, sometimes that resets the connection. Toggling means to set it to any of the other options, save the config, and then set it back to the original option.

I would contact the ISP again and insist to check on their side...

That said, who is your ISP, and what country are you in ?

[SOLID]

Hello Georg

Thank s for your response but the issue is still not resolved.

any other assistant is highly appreciated. 

[Carlo Poggiarelli]

Hi ,

Please post the running config and a show isdn status .

Thanks

Regards

Carlo

[SOLID]

Hi Carlo

thanks

[Carlo Poggiarelli]

Hi ,

I need a screenshot from CUCM of gateway configuration.

Please post it here

Thanks

Regards

Carlo

[SOLID]

Hi Carlo

SRST-HQ#

This is the ISDN STATUS:

SRST-HQ#
SRST-HQ#sh isdn stat
Global ISDN Switchtype = primary-net5

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

ISDN Serial0/0/0:15 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 = TEI_ASSIGNED
Layer 3 Status:
0 Active Layer 3 Call(s)
Active dsl 0 CCBs = 0
The Free Channel Mask: 0xFFFF7FFF
Number of L2 Discards = 0, L2 Session ID = 12
Total Allocated ISDN CCBs = 0
SRST-HQ#

[Carlo Poggiarelli]

Hi,

From what is showed on your output "TEI = 0, Ces = 1, SAPI = 0, State = TEI_ASSIGNED" it demonstrates that your E1 circuit is not established and that's why you can't receive any call.

This issue is usually generated by a misconfiguration of isdn parameters (encoding, circuit type).

I saw that you are using MGCP as protocol with your cucm and you should check the configuration there.

Can you please post a screenshot of your gateway configuration on CUCM?

Thanks

Regards

Carlo

[SOLID]

Hi Carlo

Here is it

[Roger Kallberg]

@SOLID Carlo is asking you for a screenshot of the gateway and interface configuration from your Communication Manager, not from your IOS gateway.

[Mohammed-A.R.A]

35 Line Code Violations, 864 Path Code Violations,
20 Slip Secs, 9 Fr Loss Secs, 22 Line Err Secs, 0 Degraded Mins,

We see slip seconds and violations.
Check Switch type, line code and framing, confirm with Telco.
Collect 'debug isdn q921' and notify Telco that you are receiving these messages.
Cross check that they are using isdn protocol-emulation as network?

Regards,

[Carlo Poggiarelli]

Hi,

This is the running configuration of the VG but I need a screenshot from the CUCM.

Here an example

Can you provide it ?

Thanks

Regards

Carlo

[Carlo Poggiarelli]

Hi,

On that page click on the E1 port icon (next to 0/0/0) and post a screeshot of all configuration page.

Thanks

Regards

Carlo

[SOLID]

Hi Carlo,

This is the screenshot of the E1 port