Home > IT Answers > CIO > Is Cisco Wireless .g radio backwards compatib...
GregNottage
0 pts.
 Is Cisco Wireless .g radio backwards compatible with .b?
Tech support, Hardware, Networking, Networking services, DNS, Wireless, Network protocols, DHCP, Cisco, Routers
Hi,

Please can someone tell me whether the AIR-MP21G-E-K9 802.11g radio that we have in our Cisco 1200 series access point supports both 802.11g and 802.11b clients?

If so, do I need to do anything to the running-config of the device to support both types of client?

Thanks in advance.

Greg.
ASKED: Aug 24, 2005  9:10 AM GMT
UPDATED: August 25, 2005  1:01:25 PM GMT
RELATED QUESTIONS
ItDefPat1
0 pts.
Answer Wiki:
It "should" be. I'm not an expert on that specific equipment, but a .11G AP should be able to support .11B Clients. The first catch is that .11b clients will be slower than .11g clients. See searchmobilecomputing.com for a lot of information (I found one article going in to login: http://searchmobilecomputing.techtarget.com/tip/1,289483,sid40_gci1116650,00.html?bucket=ETA
that might be a direct answer.
Last Wiki Answer Submitted:  Aug 24, 2005  9:33 AM (GMT)  by  ItDefPat1   0 pts.
To see other answers submitted to the Answer Wiki View Answer History.
RSS - Discussions Help
Discuss This Question:
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _



 

I don’t know that specific device, but I’m fairly sure it is. See the Cisco product information for details: http://www.cisco.com/en/US/products/hw/wireless/ps4570/products_data_sheet0900aecd801b9233.html .

Also, 802.11g is backwards compatible with 802.11b.

mrmobile
 0 pts.
 

Greg:

As I recall, the only problem with using 11b devices in an 11g WLAN is it will force all devices to run at 11b speeds. In the Cisco labs running only 11b, I was able to use my laptop with 11g with no special considerations.
rt

astronomer
 0 pts.
 

11g will by design support 11b. However 11b will slow down the network. I recommended and purchased 13 pcmcia running 11g at a good price and replaced the 13 11b clients and the network cruises now.

HatcherBob
 0 pts.
 

By the specs, 802.11g MUST be compatible with 802.11b. One huge drawback is that the access points can only do one or the other. So if you have many happy campers using the g range and one user comes along with a b card, everybody reverts to b speeds, an equally divided 54 meg down to 11 meg total speed through the access point. So if you have 10 users on g, they get 5 meg each. When it reverts to b, they get sucked down to a little over a meg each. Hopefully, when WiMax is fully ratified, the speed can come up to something real per user.

larrythethird
 0 pts.