Re: AuditCapability reply exceeds MTU size

Sachin,
 
>What is the maximum MTU size the gateway supports?. 
 
this is the wrong way in trying to solve the underlying problem ("using
a non-segmenting transport technology for H.248 Message sizes above the
allowed L4 SDU size") IMO.
 
Parameter MTU is link layer technology specific, there might be multiple
different L2 technologies below the H.248 Control Association (CA).
Even worse: an H.248 entity may be realized as multihomed IP host (see
also H.Sup7) for a single H.248 application, different H.248-over-IP
packets (of the same CA) could then use different IP routes and thus IP
interfaces of the H.248 MG (or MGC). And each IP interface could use a
different L2 technology (e.g. Ethernet, 802.3, ATM) with a different
max. MTU size.
 
I do thus agree to Raphael in notifying such a situation just by an
error code.
 
The problem itself should be solved by e.g. either
a) using a segmenting transport technology (e.g. SCTP => H.248.4)
b) using the H.248 segmentation package in case of non-segmenting
transport technologies or
c) limiting wildcarding options for particular commands by H.248 profile
specifications.
 
BR, Albrecht
 


________________________________

	From: [email protected] [mailto:[email protected]]
On Behalf Of Sachin
	Sent: Dienstag, 6. Mai 2008 14:21
	To: Raphael Tryster
	Cc: [email protected]
	Subject: Re: [Megaco] AuditCapability reply exceeds MTU size
	
	
	Hi Raphael,
	 
	What is the maximum MTU size the gateway supports?. If the
gateway is sending the reply which exceeds the MTU size of the gateway
controller and it parses only a portion of the message and discards the
rest. What should be the handling at gateway controller for these
scenario.
	 
	Thanks
	Sachin
	
	 
	On 5/6/08, Raphael Tryster
<[email protected]> wrote: 

		The gateway should send as many command replies as it
can for individual terminations, and end the action reply with error
533.
		 
		If anyone else wishes to comment, please reply to this
posting rather than to the original question, so it will have a
meaningful subject line.
		 
		Raphael Tryster

________________________________

		From: [email protected]
[mailto:[email protected]] On Behalf Of Ramesh Babu Kuppili
		Sent: Tuesday, May 06, 2008 1:48 PM
		To: [email protected]
		Cc: sramanathan
		Subject: [Megaco] <No Subject>
		
		 
		H.248 Gurus,
		Some Megaco switches sends AuditCapability request for
all terms in NULL context and is not requesting for wildcarded response
as part of the request. The question is how should the gateway respond
if the response for such a request exceeds the MTU size (lets say the
gateway is configured with a large number of subscribers).

		- ramesh

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