Wireless Network

Why No Standards for Wireless Controller – Access Point communications in Wi-Fi networks?

In other words, why are Wireless Access Points always proprietary to the vendor who supplied the Wireless Controller?

Any customer who has built a large wireless network knows that all the access points and controllers deployed in their premises need to be from a single vendor to realize any kind of centralized management.

We have SIP protocol in VOIP which enables any SIP Enabled IP PBX to connect with SIP Phones from any manufacturer, while still offering a good number of features. We always had standards in the Video Conferencing industry (like the current H.264 video compression standard) that enables any VC System to make a video call with any other H.264 compliant VC System (irrespective of the vendor/make). Even in case of network switches, there are clearly defined standards that enable multiple switches from different vendors to work with each other (well, mostly).

In the Wireless Networking industry, we still have the single-vendor lock-in strategy being followed aggressively. A controller will not manage any existing access points and even if it does manage them, the management functions offered for third party access points would be very limited.

Very often, customers need to dispose of a huge number of access points (and controllers) from one vendor, if they are upgrading their Wi-Fi network with the wireless controllers/access points offered by some other vendor. Or they can operate as two distinct clouds (two separate Wi-Fi networks) that cannot be managed using a single interface. Or maybe it can, if an expensive multi-vendor access point management solution is deployed as an overlay.

According to the wireless networking vendors, access points are DUMB devices. They just have radios which transmit and relay information from the clients (computers/laptops) and it is mandatory for them interact with controllers to get all the required information.

If they are such simple devices, why not follow some minimum standards in manufacturing that would allow these DUMB access points to be controlled by any controller (irrespective of the vendor/make)?

In the VOIP industry, even two IP PBX models (made by different vendors) can interact with each other to a certain extent using SIP Trunks (again a standard). Why no such standards exist for interoperability between wireless controllers? Why should an entire batch of access points or controllers be thrown away/trashed every-time a wireless network is upgraded?

What is the IEEE and IETF doing on this?

IETF has defined a standard with RFC 5415 known as CAPWAP (Control And Provisioning of Wireless Access Points). But this standard has not been implemented aggressively, except for a handful of vendors who still do not guarantee interoperability with other vendor CAPWAP implementations!

What’s the point then? Wireless vendors are conveniently citing the lack of support for new features in this standard. And we should remember that there is a separate Wi-Fi alliance (alliance consisting of various wireless equipment vendors) which gives certification for latest standards, even before they are ratified by the IEEE. For example, that’s what happened with IEEE 802.11n. There were ‘draft-n’ certified products all over the market.

In-spite of the industry being so vibrant on these areas, little or nothing has been done to introduce standards for Controller-AP communications and Controller-Controller communications. There could only be one reason for this – Customers not demanding enough.

Are we heading towards another .doc vs .odt battle? Only in the wireless industry, there are so many different versions of .doc’s that absolutely do not understand each other!


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