Difference between bridge and wireless access point??

If you read IEEE 802.11-1999, the basic document describing how wireless LANs are structured, you will see that in effect, the access point can be a bridge. Which means, you don't have to assign different IP subnets, and use a router, to tie together the multiple wireless and wired components of a layer 2 network.

In 802.11, they talk about a Distrbution System (DS) that may be used to tie together multiple isolated (or even overlapping) Basic Service Sets (BSS). The BSS is what you might call a single WiFi LAN. And IEEE

802.11 does not limit what this DS can consist of. For example, it could be a wired Ethernet (Section 5.2.4). The combination of multiple BSSs tied together with the DS is referred to as an Extended Service Set (ESS). The message here is that there has been no mention of IP routing, or any use of a Layer 3 protocol, if you introduce multiple access points into the ESS.

IEEE 802.11 also specifies a functional box called "portal." Quoting, "To integrate the IEEE 802.11 architecture with a traditional wired LAN, a final logical architectural component is introduced-a portal. ... Portals connect between the DSM and the LAN medium that is to be integrated."

Again, no mention of any routers being required to integrate these LANs.

So, bottom line, the combination of an "access point" and a "portal," and the use of a wired Ethernet as the DS, would show that the intent of IEEE 802.11 is to allow these WiFi LANS to be bridged together, and to be bridged with other non-wireless LANs as well.

However, while 802.11 adopted the same 48-bit address standard as other 802 LANs, 802.11 does preclude the possibility that the DS does not use the 48-bit MAC address standard. So if that's the case, then even though you can bridge between separate WiFi LANS across this DS, you would not be able to bridge to hosts connected directly to the DS.

Detail: the 802.11 max length of the Frame Body is 2312 bytes, but 8 of those are used for protection (WEP). So the actual data max is 2304 per frame. As opposed to 1500 bytes for Ethernet. Some people go ballistic when they think of bridging schemes together that have different max payload capacities.

Bert

hello Bert, i badly need help.

i have got an assignment on IEEE standards. i have to list down all the IEEE standards of the wired network and the wireless network. With more than 25 references and make a powerpoint presentation on that. can u plz give me an idea or suggestions how am gonna proceed? thx loads.

Doing a search with search engine would get you a lot of info to sift through.

My suggestion is to begin by going directly to the IEEE site:

and look at what each one of those addresses. The IEEE has decided to make these available free of charge, after they have been published for 6 months. This list is not complete, but they are the standards that are most relevant today (with the possible exception of 802.5). You can read the initial sections to get an idea of what each standard discusses.

That gives you a good basis, and then you can add others that you find in the more general search.

Bert

Lots of excellent information, and thanks for IEEE 802 link in your response to Nafeesa. Appreciate it :)

--Gary

You know, I cringe whenever I see these sorts of requests.

This sounds to me like you are a student at the post-secondary (college) level in some kind of technical program of study.

Why aren't you equipped with the basic skills to research an assignment instead of expecting someone to hand you all the raw materials ? This seems more prominent, but certainly not exclusive, to those with foreign names --- and I wonder if it is not a cultural thing as well as a general lowering of the bar in our "educational" institutions.

And why are you asking here ? Don't you have a professor, instructor, T.A., whatever for this class ? Didn't you ask them ? What did they tell you ? They should certainly have a good idea of what resources are available at your campus, and how to go about making the best use of them.

Admittedly, "u plz" and "thx" gives me a pretty accurate sense of your existing English language skills....regardless of wherever you hail from.

Good luck with the assignment.

Justa Lurker wrote: ...

Sorry to say but his/her lingo is historically liable to carry over to the mainstream, someday.

Living languages do evolve over time.

In this case, though, I figured that the shortened words are the offspring of cell phone text messaging. It's becoming quite prevalent even in e-mail and the usenet.

Hey, sit in a classroom and text message all day long, and the new lingo will make a lot of sense!

Bert