Urel, a TCP option for Unreliable Streaming. Need your help.

[Randall Stewart]

Ivo Vachkov wrote:
> On 12/7/06, Michael Tuexen <Michael.Tuexen at lurchi.franken.de> wrote:
> 
>>
>> Hi Andre,
>>
>> see my comments in-line.
>>
>> Best regards
>> Michael
>>
>>
>> SCTP has a extension called PR-SCTP, which is implemented in BSD
>> and can be used to limit the number of retransmissions of a
>> DATA chunk to 0. The service you mention above is therefore available
>> in SCTP.
> 
> 
> 
> 
> There is only one problem with that - you need to do a major rewrite of 
> your
> current software to use SCTP 

No, I disagree here.. we designed the API of SCTP to
literally be completely compatible with TCP..

You do

sd = socket(AF_INET, SOCK_STREAM, 0);

change this to

sd = socket(AF_INET, SOCK_STREAM, IPPROTO_SCTP);

and you now have SCTP .. if you use a socket option
or two (no delay for example) you will have to change
this to the SCTP equivlant.. which are conviently named
the smae with SCTP_ at the prefix...

There is also a shim layer that makes it so you can do both
TCP and SCTP (trying SCTP first).. but thats not ready yet.. ;-)


and hope that all OSs it's supposed to run
> on/with have SCTP support (and it's enabled).

Ahh.. well there is that.. all O/S's (current ones at least)
support SCTP with the exception of WinDoz..

You can add a package to WinDoz to make SCTP run on it.. but
no one likes to do that :-)

And besides.. if you are doing partial reliable TCP do you
really think you can do it without both ends supporting it?

The same problem would exist here..

R
> 


-- 
Randall Stewart
NSSTG - Cisco Systems Inc.
803-345-0369 <or> 803-317-4952 (cell)