Cisco Support Community
cancel
Showing results for 
Search instead for 
Did you mean: 
Announcements

Welcome to Cisco Support Community. We would love to have your feedback.

For an introduction to the new site, click here. If you'd prefer to explore, try our test area to get started. And see here for current known issues.

New Member

E1 errors

Hi,

I have these problems on E1 link with my PSTN provider:

1) sometimes, when I make an outside call, I hear that the other side answers but the call drops immediately

2) sometimes when I make an outside call, I receive the busy signal. I notice that we are never used all the channels of E1 link.

These are our architecture:

- Cisco Call Manager v.4.1 sr.7

- Voice gateway Cisco 2851 IOS spservicesk9-mz.124-8

- E1 connection with PSTN provider via MGCP and VWIC-2MFT-E1 module

as attachments, there are today reports from "show controllers e1" and RTMT.

In these outputs I notice some errors.

Is it possible that the problems that I've listed are connected with these errors?

thanks in advance

antonio

  • IP Telephony
9 REPLIES
Hall of Fame Super Gold

Re: E1 errors

have you configured network-clock-participate and -select ?

New Member

Re: E1 errors

Yes,

these are the lines:

network-clock-participate wic 0

network-clock-participate wic 1

network-clock-participate wic 2

network-clock-participate wic 3

network-clock-participate aim 0

network-clock-select 1 E1 0/0/0

network-clock-select 2 E1 0/1/0

network-clock-select 3 E1 0/1/1

network-clock-select 4 E1 0/3/0

network-clock-select 5 E1 0/3/1

The interested E1 interface is 0/0/0.

Hall of Fame Super Gold

Re: E1 errors

The issue then is with SP, even if they refuse to admit that.

New Member

Re: E1 errors

do you know if i could execute other commands to show these problems to the provider?

Hall of Fame Super Gold

Re: E1 errors

No, just show the errors in "show controllers".

Likely the will still say that everything is fine, so you have to insist, ask for a 24 bert test, etc.

New Member

Re: E1 errors

Hi,

in relation to the problem that I've explained in the first post, my provider tells me to configure my router to ask for an outbound channel to the PSTN instead of choosing it by myself.

Do you know if it is possible? What is the command?

Thanks

antonio

Hall of Fame Super Gold

Re: E1 errors

Please submit output of "debug isdn q931" with 'term mon" to prove thta router is using exclusive b-channel selection.

New Member

Re: E1 errors

This are the results:

71783: Apr 27 15:11:45.499: ISDN Se0/0/0:15 Q931: RX <- CALL_PROC pd = 8 callref = 0x83E4

Channel ID i = 0xA9839C

Exclusive, Channel 28

Progress Ind i = 0x8288 - In-band info or appropriate now available

There are other output like this.

Do I have to configure the command "isdn-negotiate bchan"?

thanks

antonio

Hall of Fame Super Gold

Re: E1 errors

It depends, if you're using MGCP, the isdn commands under interface have no effect.

However from the trace you sent, nothing shows that calls are failing due to exclusive selection being used.

275
Views
0
Helpful
9
Replies