Subject: Re: Capability Kick-off

From: [email-masked] (Thang Do)
Date: Tue, 13 Jul 93 16:33:35 PDT

As Wayne Clark wrotes

>>	In lieu of a DLSw discovery protocol, a particular DLSw would
>>	have to be configured with the IP address of all participating
>>	DLSw's (like today's 6611 is).  Also, each DLSw would have to
>>	associate a certain set of capabilities with each possible DLSw
>>	partner (keyed by IP address) so that the local DLSw would know
>>	what properties were supported remotely.

>>	For the sake of argument, let's say the capabilities exchange
>>	is UDP-based and operates somewhat like OSPF's HELLO packets.
>>	For brevity, let's call the capabilities exchange packet CAP_EXCH.
>>	When a target DLSw receives a CAP_EXCH from a previously unknown
>>	origin DLSw (as keyed by the IP address), the target DLSw issues
>>	a CAP_EXCH of its own back to the origin.

	If we use UDP for DLSw capabilities exchange, it means we must have
	an application program running on top UDP to support DLSw to reply
	all exchange messages. Therefore, we don't have a DLSw-self-contained
	
	Do all options have to be known prior to CANUREACH/ICANREACH?

	If they don't, we should use reserved bytes in control message for
	this purpose.

	Thang Do
	Novell Inc.

---

From: [email-masked]
Date: Tue, 13 Jul 93 17:05:32 PDT

>	all exchange messages. Therefore, we don't have a DLSw-self-contained

    The DLSw "application" could be sophisticated enough to manage a UDP
    port along with a couple of TCP ports.  At this tender age of the SIGlet,
    let's try to expand our thinking beyond specific machine architectures.
    If we have to come back around and restrict the possibilities, then
    we can do that later.

>	Do all options have to be known prior to CANUREACH/ICANREACH?

    Probably not.  But if you look at what's happening in the 
    Connect/Disconnect SIGlet, CANUREACH/ICANREACH at startup might not
    be mandatory.  It's too early to tell.

>	If they don't, we should use reserved bytes in control message for

    I count 10 bytes that are documented as Reserved.  Some of those bytes
    may have already been consumed by the 6611 development team as they
    added features beyond the RFC snapshot.   So we probably have less than
    10 bytes to work with.  I guess it depends on the outcome of this SIGlet
    as to whether this is enough room or not.

>	Novell Inc.

Wayne