IETF to cramp Cisco's WLAN empire?
A meeting of the Internet Engineering Task Force (IETF) standards body this week is likely to clear the way to create a standard based on the Lightweight Access Point Protocol (LWAPP), a technology backed by wireless switchmakers and NTT DoCoMo but in opposition to Cisco’s view of the wireless LAN.
The LWAPP creates a standard way for WLAN switches to communicate with ‘thin’ access points, enabling different brands of switches and APs to be combined on one network. Discovery and provisioning of APs would be automated and there would be a framework for configuring and upgrading large numbers of APs and managing sessions from a central point, all secured by IEEE 802.1x authentication.
Various technical concerns have been raised by the IETF, but the vendors are sure they have addressed these and that the body will now set up a working group to create a formal document, to be voted on in 12-18 months’ time. This is likely to rename the protocol as Control and Provisioning of Wireless Access Points (CAPWAP). A standard of this type would be a major boost for the central switch/thin AP approach, which, despite huge hype this year, has not gained great traction outside the small and medium enterprise space, partly because of the dominance of Cisco, with its fat AP architecture, in large companies.
A standard would reduce the perceived risk of adopting products from start-ups in a market that will certainly undergo shake-out in the coming year, although with a timescale of over a year, by the time it is a reality, that shake-out will already have happened, and Cisco will have come out with its own new benefits. The LWAPP initiative is seen as an attempt to counteract Cisco’s effort to establish its own WLAN technologies as de facto standards by virtue of its enterprise market share; and to give companies a risk-free alternative if they are starting to chafe under Cisco’s high prices and often dictatorial approach.
The strongest argument that Cisco always has for its moves to establish de facto standards – and therefore its own control of its key customers – is that it can move more quickly to provide the facilities that enterprises really need. It claims that the industry bodies governing WLANs, the IEEE, IETF and the Wi-Fi Alliance, do not focus specifically on enterprise needs, nor do they move rapidly enough for corporations that are looking to adapt their business models quickly to cope with new business. It has sought to establish its WLan technologies as a tickbox requirement in large sites through its CCX Extensions program.
This certifies compatibility of devices with its Aironet range, the argument being that companies can easily assemble an interoperable wireless system with common management and security frameworks – provided these are based on Cisco’s technology, which brings with it Leap, the heavy AP approach and Cisco QoS mechanisms. The LWAPP group aims to bring all the smaller players together behind a united front against Cisco, rather than leaving them to try to chip away at the giant single handed. By making APs from a host of vendors – from the fairly large players like Proxim and Symbol to the small start-ups – interoperable, this model could alter the component design and deployment business models, making systems cheaper and lowering barriers to entry, argue its supporters.
Like any multivendor process, there will be complex politics and technological debate along the way, and this one even involves multiple standards bodies. Standards like this, that concern Layers 1 and 2 of the network model, are usually the domain of the IEEE but the two bodies have worked together unusually closely on LWAPP, according to Airespace, one of a host of wireless switch start-ups, and one of the primary authors of the protocol. Including Layer 3 components – the domain of the IETF – gives LWAPP greater flexibility, allowing APs and switches to use any network, provided it supports IP, according to supporters. But this does not alter the fact that there is considerable potential overlap and conflict with the IEEE, particularly its 802.11k work in progress, which defines many resource management functions that are also central to LWAPP.
A critical decision is how to split functions such as security between the AP and the central switch or router, a split that impacts latency, a crucial measurement for time sensitive applications such as voice over IP. These functions are part of the media access control (MAC) layer, and so affect the designs of the WLAN chipmakers. But not only do most of these chipmakers support Cisco CCX, their standards are also governed by the IEEE. A long drawn out process or too many instances of in-fighting could play into Cisco’s hands and its arguments that it provides the most reliable platform for enterprise WLANs, and ensure the success of its would-be de facto standards.
© Copyright 2003 Wireless Watch
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