Re: [reSIProcate] Preserving order of attributes in sdp
Yes, we need a list to support rfc3407 (are there others?). I also agree
that it is a problem changing the interface.
I'll have a go with the patch but without the interface changes.
/Björn
Scott Godin wrote:
You are not the first person to have this problem. : )
We discussed in the past changing the AttributeHelper class to store in a list,
so that we can maintain attribute insert order. There are some properties of
the current implementation that we will need to duplicate (for backwards
compatibility), and these will end being less efficient - but I don't see a way
around this:
1. Currently attributes with like keys, are grouped together - and are
retrievable in a list via getValues() - if we want to maintain insert order
then we should no longer group attributes with like keys - but we should
maintain the getValues interface - this will mean walking the attribute list,
to form the value list to return.
2. The exists() api will need to walk the entire list.
3. Codec Format parameter attributes (a=fmtp:) and rtpmap are stored in the
Codec class - so we have less flexibility over their ordering - but this should
be ok.
Here are some older emails on the topic for reference:
http://list.resiprocate.org/archive/resiprocate-devel/msg03325.html - I don't
really like the interface change in this patch.
http://list.resiprocate.org/archive/resiprocate-devel/msg02578.html
Any thoughts?
Scott
-----Original Message-----
From: resiprocate-devel-bounces@xxxxxxxxxxxxxxx [mailto:resiprocate-
devel-bounces@xxxxxxxxxxxxxxx] On Behalf Of Björn Andersson
Sent: Monday, February 11, 2008 8:58 AM
To: resiprocate-devel@xxxxxxxxxxxxxxx
Subject: [reSIProcate] Preserving order of attributes in sdp
I'm trying to add fax-capabilities according to RFC3407, but because of
the map-implementation it is impossible to keep the order stated in the
RFC:
"The individual capability descriptions in a capability set can be
provided contiguously or they can be scattered throughout the session
description. The first capability description MUST, however, follow
immediately after the sequence number."
v=0
o=4001 866981 866981 IN IP4 148.122.211.58
s=-
c=IN IP4 148.122.211.58
t=0 0
m=audio 10628 RTP/AVP 8 0
a=rtpmap:8 PCMA/8000
a=rtpmap:0 PCMU/8000
a=ptime:20
a=cpar: a=T38FaxVersion:0
a=cpar: a=T38MaxBitRate:14400
a=cpar: a=T38FaxRateManagement:transferredTCF
a=cpar: a=T38FaxMaxBuffer:336
a=cpar: a=T38FaxMaxDatagram:176
a=cpar: a=T38FaxUdpEC:t38UDPRedundancy
a=cdsc:1 image udptl t38
a=sqn:0
There is no way to get capacity description after the sequence number.
best regards
Björn A.
--
This communication is confidential and intended solely for the
addressee(s). Any unauthorized review, use, disclosure or distribution
is prohibited. If you believe this message has been sent to you in
error, please notify the sender by replying to this transmission and
delete the message without disclosing it. Thank you.
E-mail including attachments is susceptible to data corruption,
interruption, unauthorized amendment, tampering and viruses, and we
only send and receive e-mails on the basis that we are not liable for
any such corruption, interception, amendment, tampering or viruses or
any consequences thereof.
_______________________________________________
resiprocate-devel mailing list
resiprocate-devel@xxxxxxxxxxxxxxx
https://list.resiprocate.org/mailman/listinfo/resiprocate-devel
--
This communication is confidential and intended solely for the addressee(s).
Any unauthorized review, use, disclosure or distribution is prohibited. If you
believe this message has been sent to you in error, please notify the sender by
replying to this transmission and delete the message without disclosing it.
Thank you.
E-mail including attachments is susceptible to data corruption, interruption,
unauthorized amendment, tampering and viruses, and we only send and receive
e-mails on the basis that we are not liable for any such corruption,
interception, amendment, tampering or viruses or any consequences thereof.