The Nokia E75 Says It Can Do WB-AMR over SIP

A year ago I was musing over the fact that despite there being quite a number of phones today that can do SIP over Wi-Fi, non are Wide Band AMR capable for superior sound quality. Quite a waste as without network based transcoders between the two parties there's no legacy technology to overcome and implementation is straight forward. Looks like Nokia might have changed that without making a big fuss about it:

When I recently traced the Wi-Fi SIP interaction of my new Nokia E75 (for details how this is done see here), I noticed that it announces that it's WB-AMR capable in a SIP invite message. A closer look at Forum Nokia confirmed this. Unfortunately I am missing a counterpart to try it out with but that might just be a matter of time. While my SIP provider Sipgate puts a proxy in the speech path of every call, it is capable of different codecs, as I've seen both G.711 and AMR run over it. So with a bit of luck, WB-AMR might work as well. I'll keep you posted. In the meantime, here's the E75's Session Description part of the Invite message:

Session Initiation Protocol
    Request-Line: INVITE SIP/2.0
    Message Header
    Message Body
        Session Description Protocol
            Session Description Protocol Version (v): 0
            Owner/Creator, Session Id (o): xxxxx xxxxx xxxxx IN IP4
            Session Name (s): –
            Connection Information (c): IN IP4
            Time Description, active time (t): 0 0
            Media Description, name and address (m): audio 49152 RTP/AVP 100 96 0 8 97 18 98 13
            Media Attribute (a): sendrecv
            Media Attribute (a): rtpmap:100 AMR-WB/16000
            Media Attribute (a): ptime:20
            Media Attribute (a): maxptime:200
            Media Attribute (a): fmtp:100 mode-change-period=2; mode-change-neighbor=1
            Media Attribute (a): rtpmap:96 AMR/8000
            Media Attribute (a): fmtp:96 mode-set=0,1,2,3,4,5,6,7; mode-change-neighbor=1
            Media Attribute (a): rtpmap:0 PCMU/8000
            Media Attribute (a): rtpmap:8 PCMA/8000
            Media Attribute (a): rtpmap:97 iLBC/8000
            Media Attribute (a): rtpmap:18 G729/8000
            Media Attribute (a): fmtp:18 annexb=no
            Media Attribute (a): rtpmap:98 telephone-event/8000
            Media Attribute (a): fmtp:98 0-15
            Media Attribute (a): rtpmap:13 CN/8000