Applies To:

Call2Teams - Customers


There are two primary reasons a “488 Not Acceptable Here” response is seen: Unsupported Codecs and Incompatible Encryption.



CODECS

If you see this error in the call logs, start by checking the codecs you are sending Call2Teams. You can always try limit the codecs to the most common used to see if that issue resolves. PCMU and PCMA are good choices here.


By default Call2Teams will send all codecs out from Teams to your PBX/Trunk. It can be useful to filter this to only include known good codecs.



 

  • Call2Teams provides an option in the portal to filter on the Codecs. Note that this is a restrictive filter, so codecs that are missing will not be added in. When you select the codecs here you can also order them in preference, which will then be reflected in the SDP.



                        


Codec problems: 488 Not Acceptable Here in BYE message


Example where the call dropped to "488 Not Acceptable Here" from Call2Teams is where the DTMF was negotiated in the original Invite (SDP) and the Re-Invite(SDP) had no DTMF negotiated hence, forcing Call2Teams to drop the call 


Invite SDP with DTMF negotiation

    


Re-Invite SDP without DTMF negotiation


ENCRYPTION

Confirm if you expect to send and receive calls to the Call2Teams platform using media encryption. If so, enable this in the PBX/Trunk settings page: