Date: Thu, 1 Mar 2001 15:30:51 +0100 (CET) From: Harti Brandt <brandt@fokus.gmd.de> To: Julian Elischer <julian@elischer.org> Cc: Marco Molteni <molter@tin.it>, <freebsd-net@FreeBSD.ORG> Subject: Re: How to implement a transport protocol with netgraph? (2) Message-ID: <Pine.BSF.4.33.0103011525540.37362-100000@beagle.fokus.gmd.de> In-Reply-To: <3A9E597A.D3387FC2@elischer.org>
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On Thu, 1 Mar 2001, Julian Elischer wrote: JE>Harti Brandt wrote: JE>> JE>> I have implemented SSCOP for ATM signalling in netgraph lately. If it JE>> helps you, I can send you the current code. There are however still a JE>> number of issues: JE>> JE>> - It has no socket interface yet. I plan to do one base on the ng_socket JE>> code. There should be a lot of similarities. JE> JE>why can you not use the netgraph sockets? Well, I want to be able to say fd = socket(PF_ATM, SOCK_STREAM, ATMPROTO_SSCOP); or something along that line. And netgraph sockets didn't generate flow control messages when I last locked at them (three weeks ago). JE>> - How to do flow control is not very clear up to now. There are a number JE>> of messages defined in netgraph.h for this and I have used them, but JE>> had no time to do a thourough test. JE> JE>flow control has been added to -current using the messages you saw but JE>support is still not in most nodes. Only tee and UI nodes know how to pass them JE>on... JE> JE>hopefully people who find that node type 'X' blocks their flow control messages JE>can add the code to support them to 'X' and send me the diffs :-) JE> JE>I'm also looking to add some mechanism that makes this trivial but I JE>don't know what it will be yet. Well, the problem is with the semantics of those messages. TCP, for example, thinks in bytes, SSCOP thinks in messages. So you have to generate the flow control messages differently for different consumers. (Or have them support both types). harti -- harti brandt, http://www.fokus.gmd.de/research/cc/cats/employees/hartmut.brandt/private brandt@fokus.gmd.de, harti@begemot.org To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-net" in the body of the message
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