Subject: Re: draft - ospf-scalability-03.txt

From: "Manral, Vishwas" <[email-masked]>
Date: Wed, 16 Apr 2003 01:21:17 -0400

Hi Vivek,

This has been updated in version 4 of the draft, which has recently been
completed. The current text reads: -

"      reset the Inactivity Timer for an adjacency whenever any OSPF
       packet is received over that adjacency "

Thanks,
Vishwas

-----Original Message-----
From: Vivek Dubey [mailto:[email-masked]]
Sent: Wednesday, April 16, 2003 10:33 AM
To: [email-masked]
Subject: draft - ospf-scalability-03.txt

Hi,
Section 2:
2) Reset the Inactivity Timer for an interface whenever any OSPF
    packet is received over that interface (currently this is done
only
    for the Hello packet).
    So OSPF would declare the interface to be down only if no
    OSPF packet is received over that interface for a period
    equaling or exceeding the RouterDeadInterval.

Here what the paragraph implies seems little unclear.
a) Inactivity timer are neighbor specific, so
    why should the one for interface be restarted ?
b) Why should Ospf interface be made down if no packets
    are received on it ?
c) Probably it should be something like this:
    "Reset the inactivity timer for a Neighbor whenever any
    Ospf packet is received from that neighbor"

Or i missed the point the draft tries to make ????

vivek

---

From: Erblichs <[email-masked]>
Date: Fri, 18 Apr 2003 15:35:41 -0700

Group,

        Ignoring the reasons for possibly implimenting
        the below feature...

        As a past contributor to an ARC (architecture review
        committee), a frequent question was, is that proposal
        downward scalable?

        I question whether implimentating, the ability for
        every OSPF packet over an adj to reset the Inactivity
        timer could cause more harm than good.

        Given a 50k LSDB, with a normal amount of flooding
        is isn't unlikely that we would see about 100k worth
        of update pkts per hr.

        Would 100k per hr of inactivity timer resets cause
        harm in routers?

        Does anybody else have a concern, that this type of
        item should be explicitly stated within the doc?

        With each 10 sec hello interval, I would expect to
        see 360 resets per nbr of the Inactivity timers.

        Mitchell Erblich
        Sr Software Engineer
        -------------------------------

---

From: Dave Katz <[email-masked]>
Date: Fri, 18 Apr 2003 17:03:43 -0700

This is an implementation issue.  Those who are sufficiently
clever will succeed, those who are not will fail.

Protocols like OSPF are filled with scalability issues, and the
ability to deal with them efficiently is one of the few product
differentiators.  (Full BGP routing in OSPF anyone?)