Subject: Re: [Fwd: Re: IPSP proposed text (1st approach)]

From: Dennis Niermann <[email-masked]>
Date: Wed, 31 Oct 2001 07:16:39 -0600

Brian,
You did not at all address the question I pose.
Using the diagram below, IPSP3 wants to send 
data to AS100:3.  IPSP1 and IPSP2 are the two 
possible ASPs that service that AS, but in 
override mode.
The typical M3UA message for communicating
"I am the ASP that is actively serving this/these
AS(s)" is the ASPAC message. If IPSP1 and IPSP2 
are not allowed to send an ASPAC message,
how does a remote node (IPSP3) know whether to 
send AS100:3 data to IPSP1 or to IPSP2?

/Dennis

"Brian F. G. Bidulock" wrote:
> 
> Dennis,
> 
> None of the UA drafts address how AS distribute messages
> over ASPs or visa versa.  It is expected that the ASPs
> have inter ASP communication and share AS state when
> they jointly serve an AS.
> 
> So if IPSP1 looses connection(?) to AS100:3 it should
> have a chat with IPSP2.
> 
> What you are trying to build here is a multi-point-to-
> multi-point configuration, rather than the point-to-point
> configuration proscribed in the draft.  But, keep trying.
> 
> --brian
> 
> Dennis Niermann wrote:                                     (Tue, 30 Oct 2001 17:46:17)
> > resending...
> >
> > Hi Brian,
> > I agree there is no problem with distributing SSNM messages.
> > The issue is if IPSP3 has data to send to AS100:3.
> > How does it know to send it to IPSP1 or IPSP2?
> > If they work in override mode, only one is actively
> > handling traffic for AS100:3.
> > /Dennis
> >
> >
> > "Brian F. G. Bidulock" wrote:
> > >
> > > Dennis,
> > >
> > > There is still no need (or requirement) for RC in
> > > your illustration.  Each IPSP can activate for all
> > > the AS that it supports (ASPAC without RC).
> > >
> > > Then, for example, if IPSP3 loses connection to
> > > AS201, it is ok to send DUNA(201) to IPSP1 and IPSP2.
> > > If you draw the same diagram with AS(PC201/SI3), then
> > > IPSP3 can send DUPU.
> > >
> > > Can you come up with a configuration where RC is
> > > 'required' considering the point-to-point nature of
> > > IPSPs?  It is not required in this configuration.
> > >
> > > --brian
> > >
> > > Dennis Niermann wrote:                                     (Tue, 30 Oct 2001 14:24:54)
> > > > Hi Brian,
> > > > Thanks for the challenge!
> > > >
> > > > "Brian F. G. Bidulock" wrote:
> > > >   <snip>
> > > >
> > > > >
> > > > > It is going to be tough finding a case where RC is needed at
> > > > > all for point-to-point IPSP.
> > > > >
> > > >
> > > > I believe that the following is legal since an ASP can service
> > > > more than one AS and an AS can be serviced by more than one ASP:
> > > >
> > > >
> > > >
> > > >  Figure 4:  IPSP - IPSP, multiple AS's
> > > >
> > > >
> > > >      +------+                                  +------+
> > > >      |      |                                  |      |
> > > >      | AS   |                                  | AS   |
> > > >      | 100:4|                                  | 201  |
> > > >      |      | \                              / |      |
> > > >      +------+   \  +-----+   IP   +-----+  /   +------+
> > > >                   /       \------/       \
> > > >      +------+     | IPSP1 |      | IPSP3 |     +------+
> > > >      |      +- - -\       /-+   /\       /- - -+      |
> > > >      | AS   |      +-----+   \ /  +-----+      | AS   |
> > > >      | 100:3|                 \                | 200  |
> > > >      |      |      +-----+   / \  +-----+      |      |
> > > >      |      +- - -/       \-+   \/       \- - -+      |
> > > >      +------+     | IPSP2 |      | IPSP4 |     +------+
> > > >                   \       /------\       /
> > > >      +------+   /  +---- +        +-----+  \   +------+
> > > >      |      | /                              \ |      |
> > > >      | AS   |                                  | AS   |
> > > >      | 100:5|                                  | 202  |
> > > >      |      |                                  |      |
> > > >      +------+                                  +------+
> > > >
> > > >
> > > > Is it supported for an IPSP to handle AS's with different point codes?
> > > > Anyway, let's assume that the AS100:3, AS100:4, and AS100:5 all
> > > > use the same point code but have different service indicators.
> > > > Doesn't this require IPSP1 and IPSP2 to communicate what traffic
> > > > they are handling.  E.g. by IPSP1 activating the RCs for AS100:4 and
> > > > AS100:3 and IPSP2 activating the RC for AS100:5. Otherwise, how will
> > > > IPSP3 and IPSP4 know where to send traffic?
> > > >
> > > > Regards,  Dennis
> > > >
> > > >
> > > > ---
> > > > You are currently subscribed to sigtran as: [email-masked]
> > > > To unsubscribe send a blank email to [email-masked]
> > >
> > > --
> > > Brian F. G. Bidulock
> > > [email-masked]
> > > http://www.openss7.org/
> > >
> > > ---
> > > You are currently subscribed to sigtran as: [email-masked]
> > > To unsubscribe send a blank email to [email-masked]
> >
> > --
> > ---------------------------------------------------------------
> >  Dennis Niermann              [email-masked]
> >  Ericsson Network Systems
> >  Richardson, Tx 75081
> >
> >
> > ---
> > You are currently subscribed to sigtran as: [email-masked]
> > To unsubscribe send a blank email to [email-masked]
> 
> --
> Brian F. G. Bidulock
> [email-masked]
> http://www.openss7.org/
> 
> ---
> You are currently subscribed to sigtran as: [email-masked]
> To unsubscribe send a blank email to [email-masked]

-- 
---------------------------------------------------------------
 Dennis Niermann              [email-masked]
 Ericsson Network Systems   
 Richardson, Tx 75081

---
You are currently subscribed to sigtran as: [email-masked]
To unsubscribe send a blank email to [email-masked]