Question about an communication issue between SCCP and SIP phones. We have an UCM6.x and three SCCP phones and a lot of SIP phones. The SCCP phones are 1 7960G, 1 7965G and 1 7911G. Only the 7911G phone has bi-directional audio with the sip phones. The other phones only have one way audio. So we can hear the SCCP phone talk on our SIP phone but the SIP phone is not heard on the SCCP phone. We are not in an routed environment because all is in LAN, so routing could not be the problem. We already tested with the Codec but that also does not make any difference ?
Does anybody have an idea why the 7911G is working and the other ones not.
I already updated both the 7960G and 7965G phones to the latest available firmware possible.