Mixed TCH/F and TCH/H issues

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Alexander Chemeris alexander.chemeris at gmail.com
Thu Sep 12 10:06:32 UTC 2013


Hi Andreas,

We were testing TCH/H yesterday and stumbled upon an issue when a call
is made between TCH/F and TCH/H.
 - When the call is from TCH/F to TCH/H, it doesn't connect.
 - When the call is from TCH/H to TCH/F, it connects, but voice
quality is bad - sounds like 50% packet loss.

Logs and localhost Wireshark captures of calls in both directions are here:
http://ipse.chemeris.ru/osmo-captures/dumps.tar.xz
Do you see what's wrong with them?

Our configuration was
 *  Dual-TRX with 1 TCH/F and 14 TCH/H channels. We have to keep some
TCH/F channels, since there are old phones which doesn't support
TCH/H.
 * Codecs enabled were FR, AFS and AHS.
 * LCR was connected to the MNCC socket, but in the case of
TCH/F->TCH/H call I didn't see it coming to LCR at all.

-- 
Regards,
Alexander Chemeris.
CEO, Fairwaves LLC / ООО УмРадио
http://fairwaves.ru




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