All of lore.kernel.org
 help / color / mirror / Atom feed
From: William Manley <william.manley@youview.com>
To: <linux-kernel@vger.kernel.org>
Cc: <davem@davemloft.net>
Subject: IGMP Unsolicited Report Interval too long for IGMPv3?
Date: Mon, 22 Jul 2013 11:50:09 +0100	[thread overview]
Message-ID: <51ED0E61.30106@youview.com> (raw)

If an IGMP join packet is lost you will not receive data sent to the 
multicast group so if no data arrives from that multicast group in a 
period of time after the IGMP join a second IGMP join will be sent.  The 
delay between joins is the "IGMP Unsolicited Report Interval".

In the kernel this seems to be hard coded to be chosen randomly between 
0-10s.  In our use-case (IPTV) this is too long as it can cause channel 
change to be slow in the presence of packet loss.

I would guess that this 10s has come from IGMPv2 RFC2236, which was 
reduced to 1s in IGMPv3 RFC3376.

There was a thread about this on linux-rdma in 2010 in the context of IP 
over Infiniband but it seems no patches got applied as a result of the 
discussion:

http://www.mail-archive.com/linux-rdma@vger.kernel.org/msg05740.html

Would the right patch reducing the unsolicited report interval for 
IGMPv3 be acceptable now?

Thanks

Will



             reply	other threads:[~2013-07-22 10:51 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-07-22 10:50 William Manley [this message]
2013-07-22 20:17 ` IGMP Unsolicited Report Interval too long for IGMPv3? David Miller
  -- strict thread matches above, loose matches on Subject: below --
2013-07-22 20:43 William Manley
2013-07-22 21:09 ` Ben Hutchings
2013-07-22 21:18 ` Benjamin LaHaise
2013-07-22 21:51   ` Hannes Frederic Sowa
2013-07-25 23:42     ` David Miller
2013-07-26 13:11       ` Benjamin LaHaise
2013-07-26 15:06         ` Hannes Frederic Sowa
2013-07-26 15:15           ` Benjamin LaHaise
2013-07-22 22:06   ` Lukas Tribus
2013-07-22 22:30     ` Hannes Frederic Sowa

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=51ED0E61.30106@youview.com \
    --to=william.manley@youview.com \
    --cc=davem@davemloft.net \
    --cc=linux-kernel@vger.kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.