There are no drafts or recommendations mandating that ptime be a particular value because the desired packetisation duration is closely related to the frame size and other characteristics of particular codecs.
However, almost no media gateway equipment out there will support anything other than the usual 10-30 ms for the usual suspects - G.711u/A, G.729A, etc. There are certain recommendations or mandates for ptime values based on particular codecs. For instance, 20 ms is recommended when using Speex (http://www.speex.org/docs/manual/speex-manual/node14.html): --- 4.1.1. Registration of media type audio/speex Media type name: audio Media subtype name: speex Required parameters: None Optional parameters: ptime: see RFC 4566. SHOULD be a multiple of 20 msec. maxptime: see RFC 4566. SHOULD be a multiple of 20 msec. Sachin Rastogi wrote: > Hi All, > Is there any rfc/draft or recommendation which suggests that 'ptime' > value should multiple of 5 or 10? Can I use 'ptime' value as 11 or 12 or 18 > or 19? > > > > Thanks > Sachin Rastogi > _______________________________________________ > Sip-implementors mailing list > [email protected] > https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors -- Alex Balashov Evariste Systems Web : http://www.evaristesys.com/ Tel : (+1) (678) 954-0670 Direct : (+1) (678) 954-0671 Mobile : (+1) (706) 338-8599 _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
