[SIPForum-discussion] Can SIP Layer handle Fragmentation

[mohab emara]

Hello Usman,

Section 18 of the RFC3261 discuss this issue from clients and Server
perspective, and bottom line if the message MTU size is bigger than the MTU
size handled by UDP it should be sent via TCP.

And as you mentioned it is not SIP functionality as far as i know and as you
said.
Hope this helps.

Br,
Mohab


On Thu, Sep 11, 2008 at 9:35 AM, usman chaudhry <usman_chaudhry at yahoo.com>wrote:

>  Hello Guys,
>
>     It is my understanding that SIP (RFC 3261) cannot handle fragmented
> packets. It is the responsibility of the lower layer protocols to do the
> packet reassembly i.e. for SIP via UDP it will be the IP layer that
> reassembles and for SIP via TCP it will be the the IP/TCP layer.
>
>     Can you please confirm if there is any requirement on the SIP Stack to
> reassemble fragmented SIP packets (i.e. Frames).
>
> Regards
> Usman
>
> ----- Original Message ----
> From: mohab emara <mohabemara at gmail.com>
> To: Stewart Bunce <Stewart.Bunce at telsis.com>
> Cc: usman chaudhry <usman_chaudhry at yahoo.com>; discussion at sipforum.org
> Sent: Thursday, September 11, 2008 4:36:34 AM
> Subject: Re: [SIPForum-discussion] Contact Header being changed by a SIP
> Prxy.
>
> Agree with Stewart, and find below the filtered data from table 2
> concerning this point
>
>    Header field          where   proxy ACK BYE CAN INV OPT REG
> ___________________________________________________________       Contact
> R            o   -   -   m   o   o       Contact                1xx
> -   -   -   o   -   -       Contact                2xx           -   -   -
> m   o   o       Contact                3xx      *d*    -   o   -   o   o
> o       Contact                485           -   o   -   o   o   o
>
> Where Bold d stands for delete only.
>
> Br,
> Mohab
>
>
> On Wed, Sep 10, 2008 at 4:02 PM, Stewart Bunce <Stewart.Bunce at telsis.com>wrote:
>
>>  According to Table 2: Summary of header fields, A--O in RFC3261 a Proxy
>> can only modify the Contact header field in 3XX responses and even then it
>> is only allowed to delete it/them not modify.
>>
>> Stew
>>
>> -----Original Message-----
>> *From:* discussion-bounces at sipforum.org [mailto:
>> discussion-bounces at sipforum.org]*On Behalf Of *usman chaudhry
>> *Sent:* 10 September 2008 10:41
>> *To:* discussion at sipforum.org
>> *Subject:* [SIPForum-discussion] Contact Header being changed by a SIP
>> Prxy.
>>
>> Hello All,
>>
>>     According to RFC 3261 is a SIP proxy allowed to change the Contact
>> Header for an INVITE
>>
>> regards
>> Usman.
>>
>>
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