How to block codecs in dial plans? *SOLVED*

KentC · Last edited by KentC on Tue Sep 18, 2012 3:38 pm; edited 3 times in total

1. Brekeke Product Name and version:
Sip Server 2.x|3.x
2. Java version:
Any
3. OS type and the version:
Any
4. UA (phone), gateway or other hardware/software involved:
N/A
5. Select your network pattern from http://www.brekeke-sip.com/bbs/network/networkpatterns.html :
Any
6. Your problem:

In the dial-plan, how do you block codecs that are unsupported like GSM so they are not passed through the proxy?

Thank you!

Kent C.

tuie2 · Brekeke Talented Joined: 23 Jan 2009 Posts: 57

Use $body in the Matching Pattern.

KentC · Posted: Mon Sep 17, 2012 12:03 pm Post subject:

Thank you for the help! I will save and test, then update if this is solved!

Kent C.

tuie2 · Brekeke Talented Joined: 23 Jan 2009 Posts: 57

Refer to the following page. Is is the list of codec payload types.
http://www.iana.org/assignments/rtp-parameters/rtp-parameters.xml#rtp-parameters-1

KentC · Posted: Mon Sep 17, 2012 12:40 pm Post subject:

Matching Patterns

$addr = *\.*\.*\.*
$request = INVITE
$body = ( "(m=audio .+ RTP/AVP.* 3 )" ) = .+
From = sip:(.+)@

Deploy Patterns

From = sip:(.+)@ 	To=sip:210xxxxxxx@IP
$rtp = true

When i add the $body, the call fails pretty fast.
I did run a trace and that blocked the call all together. I will test to a different term and see if that works. Does the plan above look ok?

When I remove that $body, call completes.

This is traveling like this:

Orig Carrier > Carrier Proxy > Our Proxy > Term Carrier

I have it configured to go through both proxies. Any additional help is appreciated.

tuie2 · Brekeke Talented Joined: 23 Jan 2009 Posts: 57

> $body=( "(m=audio .+ RTP/AVP.* 3 )" ) = .+

It is wrong..
It must be
$body( "(m=audio .+ RTP/AVP.* 3 )" ) = .+

KentC · Posted: Mon Sep 17, 2012 3:41 pm Post subject:

False Positive. Still not working with dial-pattern addon setup as specified.

tuie2 · Brekeke Talented Joined: 23 Jan 2009 Posts: 57

KentC · Posted: Mon Sep 17, 2012 9:20 pm Post subject:

Hey, I retested and found it was taking another rule that was working. I disabled the rule and now those that I thought with that codec that would work aren't.

Can you please advise what else could be the issue.

I tried with a second DID i have configured that works no problem with that code added and it also fails. Any helps is greatly debted. Thank you.

EDIT - When I did a pcap, it's showing '404' not found with that $body string text placed.

Kent C.

tuie2 · Brekeke Talented Joined: 23 Jan 2009 Posts: 57

Can you paste your rules here?

If you are using Brekeke ver3, set "dialplan.debug.log=true" in the Config's Advanced page for debugging DialPlan.

KentC · Posted: Tue Sep 18, 2012 9:21 am Post subject:

tuie2 · Brekeke Talented Joined: 23 Jan 2009 Posts: 57

Are you sure that the INVITE's SDP indicates GSM as a codec?
If not, the above rule doesn't match and "404" will be returned.

Can you paste the SDP part of INVITE here?

KentC · Posted: Tue Sep 18, 2012 10:40 am Post subject:

KentC · Posted: Tue Sep 18, 2012 11:00 am Post subject:

Tested with your advice and now the call completes. Does that look right to block G.729? Where can i see if its blocked? Would it show that it's actually blocked on Brekeke or just the INVITE SDP of the trace pcap? I didn't see where to find that.

tuie2 · Brekeke Talented Joined: 23 Jan 2009 Posts: 57

Yes. the payload type 18 means G729.
(See http://www.iana.org/assignments/rtp-parameters/rtp-parameters.xml#rtp-parameters-1)

> Where can i see if its blocked?

If the above rule matches, its Deploy Patterns will be executed.

If you want to debug DialPlan rules, I recommend that you use brekeke v3 because it has DialPlan History feature.

KentC · Posted: Tue Sep 18, 2012 12:53 pm Post subject:

Thank you for all your help. I will study this more and try the new version of brekeke.

This is fully resolved.