[SIPForum-discussion] SDP Parameters - Syntax Issue

[Karp Lika]

Hello,
I have a couple of questions regarding the SDP parameters in SIP
message.
Will appreciate if someone can answer the questions, or refer to the
relevant documents:

1) Is ";" sign allowed at the end of the SDP line?
Example:
  m=audio 5124 RTP/AVP 98
  a=rtpmap:98 amr/8000
  a=fmtp:98 mode-set=7; octet-align=1; 
According to RFC 2327,   Appendix A, SDP Grammar, it seems to be legal:
attribute=(att-field":"att-value) | att-field
att-field=1*(alpha-numeric)
att-value=byte-string
byte-string=1*(0x01..0x09 | 0x0b | 0x0c | 0x0e..0x0ff); any byte except
NUL, CR or LF

But, according to draft-ietf-avt-rtp-mime-06, Section 3:
"Any payload-format-specific parameters go in the SDP "a=fmtp"
attribute. The set of allowed parameters is defined by the RFC that
specifies the payload format and MUST NOT be extended by the MIME
subtype registration without a corresponding revision of the payload
format specification. The format and syntax of these parameters may also
be defined by the payload format specification, but it is suggested that
the parameters be copied directly from the MIME media type string as a
semicolon separated list of parameter=value pairs. For payload formats
that specify some other syntax for the fmtp parameters, the registration
of that payload format as a MIME subtype must specify what the
parameters are in MIME format and how to map them to the SDP "a=fmtp"
attribute".
If the client we're working with adds that sign, should our SIP entity
ignore it, or it should be reported as a problem to the Client?

2) Are two fmtp lines for same codec allowed in SDP body part? Is there
any document that defines/restricts that?
Example:
  m=audio 5100 RTP/AVP 4
  a=rtpmap:4 g723/8000
  a=fmtp:4 annexa=yes
  a=fmtp:4 bitrate=6.3

3) May bitrate parameter value for G723 codec be set to "6300" in SDP
(like a=fmtp:4 bitrate=6300)?
According to draft-ietf-avt-rtp-mime-06, 4.1.3 "bitrate: the data rate
in kb/s used or preferred for the audio bit stream, with permissible
values 5.3 or 6.3". 


Thanks a lot,
Lika
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