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Network Performance Isolation in Data Centres using Congestion Exposure (ConEx)

The information below is for an old version of the document.
Document Type
This is an older version of an Internet-Draft whose latest revision state is "Expired".
Expired & archived
Authors Bob Briscoe , Murari Sridharan
Last updated 2013-01-10 (Latest revision 2012-07-09)
RFC stream (None)
Stream Stream state (No stream defined)
Consensus boilerplate Unknown
RFC Editor Note (None)
IESG IESG state Expired
Telechat date (None)
Responsible AD (None)
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This Internet-Draft is no longer active. A copy of the expired Internet-Draft is available in these formats:


This document describes how a multi-tenant data centre operator can isolate tenants from network performance degradation due to each other's usage, but without losing the multiplexing benefits of a LAN- style network where anyone can use any amount of any resource. Zero per-tenant configuration and no implementation change is required on network equipment. Instead the solution is implemented with a simple change to the hypervisor (or container) on each physical server, beneath the tenant's virtual machines. These collectively enforce a very simple distributed contract - a single network allowance that each tenant can allocate among their virtual machines. The solution is simplest and most efficient using layer-3 switches that support explicit congestion notification (ECN) and if the sending operating system supports congestion exposure (ConEx). Nonetheless, an arrangement is described so that the operator can unilaterally deploy a complete solution while operating systems are being incrementally upgraded to support ConEx.


Bob Briscoe
Murari Sridharan

(Note: The e-mail addresses provided for the authors of this Internet-Draft may no longer be valid.)