Re: Comment/question on draft-ietf-sip-body-handling-01.txt

   From: Hadriel Kaplan <HKaplanacmepacket.com>

   > RFC 3261 section 18.1.1 currently provides a
normative minimum:
   > "However, implementations MUST be able to
handle messages up to the
   > maximum datagram packet size.  For UDP, this size is
65,535 bytes,
   > including IP and UDP headers."

   Yes.  That section of 3261 is about messages - it says
nothing
   about bodies.  Some devices reject requests with bodies
that exceed
   a length, where that length is less than the full 64k for
the whole
   message.  For example, one of my companies' products will
reject a
   SIP message with an overall body bigger than 32KB by
default.  It's
   configurable, but I think we're compliant to reject such
by
   default.

That seems a strange restriction to me -- though it accepts
some
messages of 64k length, they must include 32kb of headers in
order to
do so.  32kb of headers is even scarier than a 1Mb of
body...

Dale
_______________________________________________
Sip mailing list  https://www
.ietf.org/mailman/listinfo/sip
This list is for NEW development of the core SIP Protocol
Use sip-implementorscs.columbia.edu for questions on current
sip
Use sippingietf.org for new developments on the application of
sip

> -----Original Message-----
> From: sip-bouncesietf.org [mailto:sip-bouncesietf.org]
On Behalf Of
> Dale.Worleycomcast.net
> Sent: Tuesday, March 18, 2008 3:32 PM
> To: sipietf.org
> Subject: Re: [Sip] Comment/question on
draft-ietf-sip-body-handling-01.txt
>
>    From: Hadriel Kaplan <HKaplanacmepacket.com>
>
>    > RFC 3261 section 18.1.1 currently provides a
normative minimum:
>    > "However, implementations MUST be able to
handle messages up to the
>    > maximum datagram packet size.  For UDP, this
size is 65,535 bytes,
>    > including IP and UDP headers."
>
>    Yes.  That section of 3261 is about messages - it
says nothing
>    about bodies.  Some devices reject requests with
bodies that exceed
>    a length, where that length is less than the full
64k for the whole
>    message.  For example, one of my companies' products
will reject a
>    SIP message with an overall body bigger than 32KB by
default.  It's
>    configurable, but I think we're compliant to reject
such by
>    default.
>
> That seems a strange restriction to me -- though it
accepts some
> messages of 64k length, they must include 32kb of
headers in order to
> do so.  32kb of headers is even scarier than a 1Mb of
body...

Not if you look at IMS messages. ;)
Yeah, I don't know why it's 32KB by default, but it is. 
Probably some random number generator.  Or a trade-off
between "protect weak boxes" and
"make-it-workie".  Regardless, without a BCP there
was nothing to go by. (not that I'm saying a BCP would make
us change behavior, but we try to be good)

-hadriel
_______________________________________________
Sip mailing list  https://www
.ietf.org/mailman/listinfo/sip
This list is for NEW development of the core SIP Protocol
Use sip-implementorscs.columbia.edu for questions on current
sip
Use sippingietf.org for new developments on the application of
sip