One way audio problems

Asterisk Asterisk Support
1

Hi,

We have the following problem: in random calls from a phone to PSTN and viceversa, the audio received in the PSTN side becomes badly and noise making it impossible to understand.

We’ve done some testing, measuring about 30% of Drop by Jitter buffer using Wireshark, but we don´t know why it happens, anyone can help us?

We have the following topology:

<- SIP -> <- IAX -> <gateway (1TE820BF)> <- E1 ->

The Proxy and Gateway are Dell R310 (Xeon X3450 2.66GHz 4 cores, 4G RAM) with Asterisk 11 connected to a switch PowerConnect 5548 with 10 Mbps to internet and 1Gpbs between both, using 2 NIC cards (bonding).

The phone is a Cisco SPA3102 Phone Adapter with 10 Mbps to internet.

Proxy/Gateway and phone are connected to different ISPs in Chile.

During testing, we have 1 or 2 calls simultaneously.

Regards,
Christian

2

I’d start with a traceroute between the end points to look for excessive latency or jitter

3

This isn’t one way audio, as normally understood.

Are you actually dropping frames, or is Wireshark just throwing them away.

If the latter, has there been a timestamp discontinuity, with no correponding change in SSRC. Asterisk does that but some Cisco phones don’t like it.

4

Hi,

I made a traceroute from a laptop in the same network as the phone to de sip proxy:

traceroute to X.X.X.X (X.X.X.X), 64 hops max, 52 byte packets
 1  192.168.0.1 (192.168.0.1)  2.172 ms  1.810 ms  1.787 ms (0% loss)
 2  * * * (100% loss)
 3  192.168.224.234 (192.168.224.234)  31.195 ms  31.251 ms  12.599 ms (0% loss)
 4  192.168.22.45 (192.168.22.45)  12.798 ms  13.900 ms  34.724 ms (0% loss)
 5  * * * (100% loss)
 6  gw-gtd.pit.ip.telmexchile.cl (201.238.238.73)  11.829 ms  14.006 ms  14.057 ms (0% loss)
 7  str12.ge1-46.cn2.gtdinternet.com (201.238.238.6)  14.904 ms  13.770 ms  13.106 ms (0% loss)
 8  190.196.126.8 (190.196.126.8)  12.229 ms  13.194 ms  13.002 ms (0% loss)
 9  X.X.X.X (X.X.X.X)  15.831 ms  14.749 ms  12.954 ms (0% loss)
5

The network is badly overloaded.