Does anyone know of a work around for the following firmware errata: "When using media anchoring, receiving a 183 Session Progress after a previous 183 on hairpinned calls can result in no early media if the SDP in the second 183 differs from the first." It showed up in firmware ~10.7 and is still present in current 12.X and 13.X firmware.
Configuration:
Carrier (Metaswitch) ---> Private Layer 2 network ---> Netvanta 3430 SBC ---> Private network ---> 7100
Carrier requires use of the SBC to be a divider between the customer private network and their private network. Since the two networks can not be routed Media Anchoring on the SBC is required.
Scenario:
Remote party calls customers DID the DID is in a ring group on the 7100. The ring group rings two internal phones if no answer by 4th ring the ring group uses coverage to forward to external cell phone. Call is successfully placed but there is no audio. Both legs of the call are using 183 session progress.