There is no fixed filed length for any SIP headers.

Instead of trying to allocate a maximum amoount of
memory for any specific headers, it would be better
to allocate yourself a big scratchpad of memory
and then copy strings into there as required.
Or something like that.

Although the maximum SIP message size is around 64k,
in practice, I don't think I've ever seen anything above
3k.  So a 6k scratchpad is enough for each call leg.

Cheers,

Attila

Attila Sipos
http://www.vegastream.com



>> -----Original Message-----
>> From: [EMAIL PROTECTED]
>> [mailto:[EMAIL PROTECTED] Behalf 
>> Of Hume Vance
>> Sent: 21 September 2006 23:21
>> To: '[email protected]'
>> Subject: [Sip-implementors] Question in re field lengths in 
>> SIP headers
>> 
>> 
>> Hi,
>> 
>> I have been unable to pinpoint a recommendation relating to 
>> sizes of fields
>> within the SIP header. The issue relates to how much memory 
>> to allocate for
>> each field as a packet is built up.
>> 
>> Section 7.3 of RFC 3261 describes header field formats, but 
>> does not discuss
>> length limitations for those fields. Beyond the limitation 
>> of the overall
>> packet length, does anyone have a recommendation for how to 
>> size the header
>> fields? In other words, is it safe to restrict a Route to 
>> 128 bytes, for
>> example? Is there a list of such safe lengths for each header field? 
>> 
>> If not, what do implementations generally support? Do they 
>> generally allow
>> arbitrary lengths of the individual header fields, as long 
>> as the total
>> packet length falls within the allowed maximum?
>> 
>> Thanks in advance,
>> 
>> Hume
>> 
>> 
>> Hume Vance
>> Director, Firmware Engineering
>> Zoom Technologies, Inc.
>> 207 South Street
>> Boston, MA 02111
>> USA
>> [EMAIL PROTECTED]
>> +1 617 753-0032
>> 
>> _______________________________________________
>> Sip-implementors mailing list
>> [email protected]
>> https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
>> 

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