Using alternate ITSP address for media/ one way audio issue

[neebsScott]

Hi,

Our ITSP insists we use one address for signalling and they've given us another to use for media. Is there somewhere to set this up in Freesbc or do we leave this to be is negotiated in call setup?

On the internal trunk to PBX I can see and playback two-way audio in wireshark. So this seems to be fine. On outside I only see audio one way and that is ITSP --> FreeSBC in trace. No RTP FreeSBC --> ITSP relaying what is taking place on the inside trunk. Am I missing something?

On softphone connected to PBX I can hear incoming audio but nothing going back out (testing with mobile). From the above traces it seems inside trunk is ok as I can see two way audio in wireshark and play it back but outside there is a relaying problem as I can only see RTP coming inbound from ITSP and nothing going back out replicating what I see inside.

----

The media address is announced in the SDP as below (have ??'d out addresses) media is 194, signalling on 193 here

SIP UDP message remote=??.??.??.193:5060 -> local=??.??.??.??:5060
v=0
o=- 262257 926108 IN IP4 ??.???.??.194
s=-
c=IN IP4 ??.???.??.194
t=0 0
m=audio 19864 RTP/AVP 8 101
a=rtpmap:101 telephone-event/8000
a=ptime:20

Call is G.711 A-law end to end.

Is there something silly I am missing?

Many Thanks,
Scott.

[Admin]

Hi

You can use different IP addresses for signaling and media. First you need to set new IP interface for signaling and media and in the NAP settings Port Range section select the RTP range for media IP. In this case signaling will go from one IP address and media will go from another IP address.

For one way audio issues you can check the following link; https://docs.telcobridges.com/tbwiki/FreeSBC_Troubleshooting#One_Way_Audio.2F_No_Audio_Problems

[neebsScott]

So I'm clear. I need to set up another IP interface on our SBC in order to relay to the separate media address the ITSP is using at their side?

[Admin]

If you want to send signaling and media from different IP addresses, yes you are riht.

[neebsScott]

Hi, it's not that we want to send on different IP addresses it's the ITSP who want to use a separate IP for themselves at their side for media.

I can't send and receive media to/from that address using same interface on our side?

It appears I can receive media from the address in the traces but media isn't being relayed back out from the SBC to ITSP.

Sorry if these are silly questions just want to make sure we understand each other

[Admin]

Hi

SBC is not caring if ITSP used different IP addresses for media and signaling. SBC will check connection information in the received SDP and start to send the RTP to that IP addresses even SIP Signaling IP is different.

[neebsScott]

OK, well that isn't happening. That's my problem.

I'm seeing two way media on the inside trunk but outside we are only seeing incoming from ITSP. traffic isn't relaying out.

[Admin]

SO you need to check the link I sent you in the first reply for one-way Audio problems. Seems to me there is a NAT issue.

[neebsScott]

We're not using NAT as the outside interface on the SBC is public. We are seeing the below in call trace though on outside leg

*** Data path errors:
- no packet sent to network
- 758 packets dropped to network due to incomplete ARP to '0.0.0.0'

After call final stats show correct IP for media for ITSP but one way audio. Two way audio inside NAP. Where is the 0.0.0.0 coming from?

Final stats (NAP 'GAMMA_NAP'): FromNetwork[ Rx=1588 Err=0 ] ToNetwork[ Tx=0 Err=1583 ] RTP-Voice+CN[ Tx=0 Rx=1588 RxErr=0 ] RTP-Event[ Tx=0 Rx=0 ]

MOS: 4.3 codec ideal MOS 4.3, Network quality: 100%
remote XX.XXX.XX.194:25242 ------ | ------ local XX.XX.XXX.12:16388
------------------------------------- 4.3 (PCMA) --------------------->
<----------------------------------- 0.0 (PCMA) -----------------------

Connection freed full-duplex with 0x0DEB465E

Endpoint freed

Terminate with cause (16-NORMAL_CALL_CLEARING)

Final stats (NAP 'THIRDLANE_NAP'): FromNetwork[ Rx=1582 Err=0 ] ToNetwork[ Tx=1580 Err=0 ] RTP-Voice+CN[ Tx=1580 Rx=1582 RxErr=0 ] RTP-Event[ Tx=0 Rx=0 ]

MOS: 4.3 codec ideal MOS 4.3, Network quality: 100%
local 192.168.20.12:10004 ------ | ------ remote 192.168.20.10:10098
------------------------------------- 4.3 (PCMA) --------------------->
<----------------------------------- 4.3 (PCMA) -----------------------

Connection freed full-duplex with 0x8DEB465D

Endpoint freed

[Admin]

Hi

Please contact with support@telcobridges.com.