Subject: Re: Internet Draft : Prioritized Treatment of Specific OSPF Pack ets and Congestion Avoidance #1

From: "Manral, Vishwas" <[email-masked]>
Date: Thu, 3 Apr 2003 10:50:22 -0500

Hi Mike,

Let me try to answer your question. I do not think the two suggestions are
exclusive.

We give priority to hellos and yet we reset the inactivity timer whenever we
get a packet from a neighbor including hellos(I dont know how they are
mutually exclusive). We do not stop sending hellos if we have sent a packet
in that hello interval already.

The point is that hello not only conveys the neighbor reachabiltiy
information but also fields like DR/BDR etc which can be of use(unlike in
BGP keepalives I guess).

Let me know if you agree?

Thanks,
Vishwas

-----Original Message-----
From: Mike Fox [mailto:[email-masked]]
Sent: Thursday, April 03, 2003 8:02 PM
To: [email-masked]
Subject: Re: Internet Draft : Prioritized Treatment of Specific OSPF
Packets and Congestion Avoidance #1

I know I am coming a little late to this conversation, having only recently
joined the mailing list.  But I did want to mention that we have had good
success with increasing the priority of hello packets.

I do think that two of the suggestions may be mutually exclusive:
increasing priority of hello packets and resetting inactivity timer on any
packet from a neighbor.  If hello packets are higher priority and the
neighbor actually did go down, do you really want to delay learning about
the neighbor outage while you work through a backlog of lower-priority
packets from that neighbor?

Mike

---

From: "Choudhury, Gagan L, ALABS" <[email-masked]>
Date: Thu, 3 Apr 2003 13:55:19 -0600

Based on the various comments so far perhaps we can point out explicitly
that if Hello packets are already being prioritized then it may not
be necessary to reset the activity timer based on receiving any packet
over the inteface since there may be other issues associated with that.
Does it address most comments?

                Gagan  

-----Original Message-----
From: Tony Przygienda [mailto:[email-masked]]
Sent: Thursday, April 03, 2003 2:43 PM
To: [email-masked]
Subject: Re: Internet Draft : Prioritized Treatment of Specific OSPF
Pack ets and Congestion Avoidance #1

> Also, please keep
>   in mind that there may be
>   situations where specially identifying Hello and prioritizing it
>   (at the receiver) may not
>   be easy but it may be easier to reset inactivity timers on receiving
>   any packet.
>
doing that (resetting timer on every packet instead of what the spec says)
may lead to very subtle interoperability problems
(and had in the past, a.k.a routers 'forgetting' to send hellos for one
or another
reason) and you may want to point that out. I don't disagree though that
it's
a good thing.

    --- tony

---

From: Mike Fox <[email-masked]>
Date: Thu, 3 Apr 2003 15:14:32 -0500

> Does it address most comments?

That works for me, though I would just expand it a teeny bit to mention
that one of the "other issues" is  decreased convergence time because doing
both may cause it to take significantly longer than the dead router
interval to discover that a neighbor has died because of the inactivity
timer being reset as stale packets in the lower priority queue are being
processed.

Mike

---

From: "Choudhury, Gagan L, ALABS" <[email-masked]>
Date: Thu, 3 Apr 2003 14:21:23 -0600

Mike,
  Thanks.  We will address your point.

                Gagan

-----Original Message-----
From: Mike Fox [mailto:[email-masked]]
Sent: Thursday, April 03, 2003 3:15 PM
To: [email-masked]
Subject: Re: Internet Draft : Prioritized Treatment of Specific OSPF

Mike