# IAX trunk not reducing bandwidth even if "trunk=yes" is set

**URL:** <https://community.asterisk.org/t/iax-trunk-not-reducing-bandwidth-even-if-trunk-yes-is-set/67149>\
**Category:** Asterisk Support\
**Created:** [June 25, 2016, 3:27am UTC](https://community.asterisk.org/t/iax-trunk-not-reducing-bandwidth-even-if-trunk-yes-is-set/67149 "2016-06-25T03:27:25Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![rkatel](https://avatars.discourse-cdn.com/v4/letter/r/a3d4f5/32.png) [@rkatel](https://community.asterisk.org/u/rkatel)\
**Post date:** [June 25, 2016, 3:27am UTC](https://community.asterisk.org/t/iax-trunk-not-reducing-bandwidth-even-if-trunk-yes-is-set/67149/1 "2016-06-25T03:27:25Z")

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Hi everybody!

I’m failing since a couple of days in making my IAX trunk work properly, I mean reduce bandwidth consumption when making multiple calls.

In fact, I made a trunk between two Asterisk servers, and subscribers from each server can call anyone from the other server without any problem.

But the problem is that, even though I have set the “trunk=yes” parameter, IAX does not multiplex the multiple calls through the trunk (I captured then analysed the packets with Wireshark). However, I have res\_timing\_dahdi and res\_timing\_timerfd running. So, I really don’t understand where is problem.

```
**42VOIPSERVER*CLI> module show like timing**
 **Module Description Use Count Status Support Level**
 **res_timing_dahdi.so DAHDI Timing Interface 0 Running core**
 **res_timing_pthread.so pthread Timing Interface 0 Running extended**
 **res_timing_timerfd.so Timerfd Timing Interface 1 Running core**
 **3 modules loaded**

```

The iax.conf :

```
;Antananarivo
[brazza]
username=brazza
type=friend
host=dynamic
context=interco
secret=pa$$w0rd
trunk=yes
;disallow=all
allow=alaw
;allow=ilbc
;allow=g729
;allow=gsm
deny=0.0.0.0/0.0.0.0
permit=10.61.10.100/255.255.255.255

```

I’m using Asterisk 13.9.1 on Ubuntu 14.04.4 running on 2 VirtualBox VMs. Does the problem comes from the fact that I use virtual machines ?

If someone could help me, it would be great !

Thank you in advance!

If someone could help me, it would be great !

Thank you in advance!

---

<div class="post-metadata">

**Author:** ![rkatel](https://avatars.discourse-cdn.com/v4/letter/r/a3d4f5/32.png) [@rkatel](https://community.asterisk.org/u/rkatel)\
**Post date:** [June 26, 2016, 12:04am UTC](https://community.asterisk.org/t/iax-trunk-not-reducing-bandwidth-even-if-trunk-yes-is-set/67149/2 "2016-06-26T00:04:47Z")

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Finally, I got the solution. The problem was that I didn’t uncomment the parameter “trunktimestamps=yes” in the iax.conf file on both servers.

Thank you anyway.