sundance-communications.com/forum Forums TDM Business Telephone Systems Samsung Telephones & Systems SMTi5220s Audio Internal Call Audio Problem

OK I’ve got a Site that is driving me mad.

When an internal call is made from Speaker phone on a SMTi5220S and the other party picks up with the receiver on a SMTi5220S the party using the receiver gets clipping / poor audio quality. I have been to site and tested several times, taking Wireshark captures, upgrading software etc

The last time I went to site I tried some different handsets including a SMTi5220S from a newer batch that was given to the speaker phone “user” and the problem went away for a while but seems to be back.

This seems to be a system wide issue, occurs when calling from different extensions to different extensions on what is a very simple setup. 7100 4.8 software, 10 x SMTi5220S handsets. Switch is Cisco SG30028P with default configuration. One flat layer 2 LAN with not a lot going on.

The only thing that comes to mind is some issue to do with the G722 wideband codec and the telephone receiver.
All other calls seem to work fine just seems to be speaker to receiver internal calls.

The 5220(s) isn't a full duplex speaker phone.

Try changing the codec to G.711

Played back Wireshark Traces and the internal calls are definitely G711 not G722.

It seems that the relatime audio in the Trace is perfect, the problem is on the 5220S telephone receiver.

I haven't seen this at other sites so not sure what is going on.