SpectraLink i640 - Manual (Page 7)

SpectraLink Corporation SIP User Agent: Features and Standards
5. Media Support
Feature Received? Transmitted?
Session Description Protocol:
v, o, s, t, m, c lines Yes Yes
Reject session if any lines unrecog No, unrecognized lines are ignored
v=0 Value is ignored Yes
Session id is NTP timestamp Accepted No, random integer
IP=0.0.0.0 as hold indicator Yes Yes, optional
‘sendonly’ as hold indicator Yes Yes
‘rcvonly’ response to ‘sendonly’ Ignored Yes
IPv6 No No
Telephone Event Signaling:
RFC 2833 Yes Yes, optional
RFC 2833 dynamic payload type Payloads ignored Yes
Inband DTMF Not detected, heard as audio No
Events signaled Ignored 0-9, #, * (Not A-D, hookflash)
INFO message signaling Ignored Yes, optional
Audio Codecs:
G.711 u-law (10, 20, 30, 60) 10, 20, 30, 60 msec frames 20 msec frames
G.711 A-law (10, 20 , 30, 60) 10, 20, 30, 60 msec frames 20 msec frames
G.729 (10, 20 30) No No
G.723.1 (30) No No
Silence suppression Ok No
Comfort Noise for G.711 Ok Yes
Comfort Noise per RFC3389 Ok No
RTCP Socket not open – unreachable No
SRTP No No
Offer / Answer Model:
INVITE without attached SDP Yes No
ACK with attached SDP Yes No
On-the-fly codec changes No No
Early audio cut-through for 183
call progress responses
Yes No
Re-INVITE to change codec Yes No
Re-INVITE to change address Yes No
Multipart MIME No No
S/MIME No No
Part Number: 72-1089-01-C.doc Page 7