Concurrent dual band routers vs single/non-concurrent dual band routers

[JoeHombre]

Folks, I’ve read that 802.11n and 802.11b/g traffic should be directed to different sub-nets because doing so will provide better overall performance.

Does this also apply for concurrent dual-band routers such as the Dir-855 and Dir-825? These routers provide up to 4 SSIDs (2 for “router mode” and 2 for “guest mode”) -- with combinations of both mixed and non-mixed b/g and n. However, these routers have one subnet address (i.e. 192.168.0.1).

On the Dir-855 and 825: would a single SSID set to mixture of 11G and 11N not impact the performance of other SSIDs set to 11N only? Or is the subnet address the controlling factor and thereby all SSIDs would be impacted?

Joe

 

[jdabbs]

Do you have a link for the subnet recommendation? Instead, you should try to segregate traffic into separate wireless broadcast domains--in the case of the 825/855, the individual 2.4 and 5 GHz radios. Different SSIDs shouldn't change performance if they're both on the same radio, as the domain would remain unchanged.

 

[thiggins]

Folks, I’ve read that 802.11n and 802.11b/g traffic should be directed to different sub-nets because doing so will provide better overall performance.

SmallNetBuilder's recommendation is that you don't run mixes of draft 11n and 11b/g clients on the same draft 11n WLAN. It doesn't have anything to do with subnets, SSIDs or broadcast domains.

The reason is due to how draft 11n has to slow down to accommodate the slower legacy traffic. The issue is similar to how 802.11g had to slow down to be able to handle 802.11b. In that case, however, the throughput difference wasn't as great.

Dual-radio products help only if you can use the 2.4GHz radio for 11b/g clients and the 5 GHz radio for draft 11n clients. That means, though, that all clients must have dual-band radios.

 

[JoeHombre]

Thanks, Tim and Jdabbs,

This is valuable info. I was considering both 2.4 GHz 11g and 2.4GHz 11n on different SSIDs plus 11n 5GHz on a 3rd SSID for a single router solution. However, network slow-down seems to nullify any combo 11g and 11n advantage for the 855 and 825 routers.

I appreciate the insight and education.

Joe

 

[jdabbs]

SmallNetBuilder's recommendation is that you don't run mixes of draft 11n and 11b/g clients on the same draft 11n WLAN. It doesn't have anything to do with subnets, SSIDs or broadcast domains.

I know the difference between a traditional Ethernet broadcast domain and what I referred to as a wireless broadcast domain (a collection of devices that share broadcasting ability: one transmits, remainder silent by necessity). However, the lack of search results for "wireless broadcast domain" indicates that's not the conventional term. What is the official name for what I described? WLAN?

 

[thiggins]

I believe it is BSS (Basic Service Set).

 

[jdabbs]

BSS looks correct. Thanks.

 

[bigclaw]

That means, though, that all clients must have dual-band radios.

I'm not sure I understand this point though. Won't most b/g clients by definition only have 2.4GHz radios?

 

[thiggins]

I'm not sure I understand this point though. Won't most b/g clients by definition only have 2.4GHz radios?

I should have said all draft N clients must have dual-band radios. Sorry.

 

[SteveStMS]

What I'm doing is running a Verizon Westell for B/G 2.4Ghz, FIOS TV and DLink DIR-655 configured as Access Point with radio set for Draft-N 5Ghz only. Is this the best solution for full speed B/G network and N in the same home?

 

[bigclaw]

What I'm doing is running a Verizon Westell for B/G 2.4Ghz, FIOS TV and DLink DIR-655 configured as Access Point with radio set for Draft-N 5Ghz only. Is this the best solution for full speed B/G network and N in the same home?

The DIR-655 has a 5GHz radio? That's news to me.