[rbak-nsp] Accepted way to shape L2TP subscribers (David Freedman)

[Ian Calderbank]

David,

I am assuming you mean L2TP LNS not L2TP LAC.

Use metering to mark and pwfq to shape on the same subscriber. You can apply
both at the same time.

Pwfq is the only way to "shape" nicely as you require. Plus of course if you
actually want priority (e.g. voice versus data) then pwfq is what you need.

Beware of limitations with l2tp lns and subscriber pwfq combined
- the l2tp packet needs to come into the box on the same card as you handle
the subscriber circuit. So you can't use the lns-card l2tp session PPA
circuit loadbalancing feature, nor can you use cross-card LAG on your trunk
carrying the l2tp out toward the LAC.
- there is no hierarchical qos support

ta 
Ian

-----Original Message-----
From: redback-nsp-bounces at puck.nether.net
[mailto:redback-nsp-bounces at puck.nether.net] On Behalf Of
redback-nsp-request at puck.nether.net
Sent: 15 December 2010 17:00
To: redback-nsp at puck.nether.net
Subject: redback-nsp Digest, Vol 36, Issue 7

Send redback-nsp mailing list submissions to
	redback-nsp at puck.nether.net

To subscribe or unsubscribe via the World Wide Web, visit
	https://puck.nether.net/mailman/listinfo/redback-nsp
or, via email, send a message with subject or body 'help' to
	redback-nsp-request at puck.nether.net

You can reach the person managing the list at
	redback-nsp-owner at puck.nether.net

When replying, please edit your Subject line so it is more specific than
"Re: Contents of redback-nsp digest..."


Today's Topics:

   1. Accepted way to shape L2TP subscribers (David Freedman)


----------------------------------------------------------------------

Message: 1
Date: Wed, 15 Dec 2010 13:40:59 +0000
From: David Freedman <david.freedman at uk.clara.net>
To: "redback-nsp at puck.nether.net" <redback-nsp at puck.nether.net>
Subject: [rbak-nsp] Accepted way to shape L2TP subscribers
Message-ID: <4D08C56B.2060305 at uk.clara.net>
Content-Type: text/plain; charset=ISO-8859-1

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

Collective,

Wondering on the commonly accepted way of shaping L2TP subscribers.

Currently am using a PWFQ policy such:

qos policy RATECAP24M pwfq
 rate maximum 24576
 num-queues 4
 queue 0 priority 0 weight 100
 queue 1 priority 1 weight 100
 queue 2 priority 2 weight 100
 queue 3 priority 3 weight 100
!

Though I understand that this is achievable with both metering and policing
policies.

Wondering what the best way to do this is, considering I would rather shape
than police (i.e be kind to TCP and avoid bandwidth "sawtooth"
oscillations caused by TCP not backing off)

Was thinking of switching to metering simply to be able to add marking to
the policy as well.

Any advice appreciated.

Dave.

- --

David Freedman
Group Network Engineering

david.freedman at uk.clara.net
Tel +44 (0) 20 7685 8000

Claranet Group
21 Southampton Row
London - WC1B 5HA - UK
http://www.claranet.com

Company Registration: 3152737 - Place of registration: England

All the information contained within this electronic message from Claranet
Ltd is covered by the disclaimer at http://www.claranet.co.uk/disclaimer
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.9 (GNU/Linux)
Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/

iEYEARECAAYFAk0IxWsACgkQtFWeqpgEZrI8cwCghHfl4GKtABI2GaIltCgGUYMO
z60AoNjkatqTClVChZPD/tReFhboRXUy
=sTQZ
-----END PGP SIGNATURE-----


------------------------------

_______________________________________________
redback-nsp mailing list
redback-nsp at puck.nether.net
https://puck.nether.net/mailman/listinfo/redback-nsp


End of redback-nsp Digest, Vol 36, Issue 7
******************************************