Re: [nznog] QoS-IXPs

Speaking with my exchange operator hat on (nzix.net): None of the NZIX exchanges support QoS at present. The standard connection to the exchange is an access port (untagged) which means we have no way of accepting 802.1p information from our customers. In the interests of hardening the exchange fabric we use a number of features (storm control, spanning tree root guard, spanning tree bpdu guard, port security, etc). Not all of these features are supported on trunk interfaces[1]. The exchanges are made up of a mixture of Cisco hardware, mostly 29xx and 35xx switches, but more recently some 3750 and ME-3400 switches. Most of these switches have only very limited QoS capabilities (2 queues?). Our approach is to over engineer the exchange fabric so congestion only really occurs at the customer access port, and that can be addressed by getting a faster port :) Another interesting difference between the NZIX and other exchanges is we operate route servers which most of the exchange participants use so there are very few bi-lateral peering sessions. We use Quagga on linux boxes for the route servers. Would we require any special options to be configured to allow propagation of the CoS BGP attributes? A couple more general questions: Why is it necessary to use a layer 2 QoS marking at all? I assume most of the traffic crossing exchanges is IPv4 with a handful of IPv6 (and maybe MPLS?), all of which have their own QoS marking schemes (TOS/DiffServ/EXP). Are there any special expectations around how QoS marked traffic will be handled by an exchange? e.g. minimum/maximum bandwidth, queuing algorithms (wrr, red), strict queuing etc, number of queues. [1] This may not be true with recent hardware/IOS revisions, but was certainly true in the past. Thanks, Dylan On Thu, 2009-03-26 at 03:16 +1300, Brian E Carpenter wrote:

On behalf of Thomas Knoll:

---------- Forwarded message ---------- Date: Wed, 25 Mar 2009 02:02:42 +0100 (MET) From: Thomas M. Knoll To: nznog(a)list.waikato.ac.nz Subject: QoS-IXPs

Dear Sirs,

excuse me please for bothering you with the following information, but I thought it could be of use for you as well.

Background: I am currently proposing a class of service signalling extension to BGP in order to enhance the current best effort AS interconnection into a simple class-based interconnection. This primitive traffic separation scheme also encompasses lower layer QoS schemes in a consistent manner, which makes it attractive for QoS interested peering partners to meet on peering platforms with Ethernet QoS support.

Therefore, I am trying to find out about Internet exchange points, which would a least transparently (untouched) transfer user priority bits across their platform and might even have 802.1p enqueueing and scheduling enabled on their switches.

Having said that, I will point you to the current QoS capable IXP list on the web. http://www.bgp-qos.org/qos-ixp/

Furthermore, if you are interested to be recognized by QoS interested peering partners as potential peering platform, I would cordially invite you to register there as well. http://www.bgp-qos.org/qos-ixp/add.php

Thank you in advance, Thomas Knoll

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