We have a 21mbps connection to the Internet. This connection has several uses, not just for wireless internet access.
The average internet speed tests I do for users not on the wireless on this connection range from 8mbps to 15mbps.
As soon as I put a wired port on a wireless vlan and or get on wireless my internet speed tests go from 1.5 mbps to 3.0 mbps.
After doing some research, I think I have figured out the bottleneck that could be causing issues.
Our wireless topology is completely separate from the rest of our internal network, except that it uses the same internet access.
Wireless VLAN/Clients --> Wireless Router (cisco 4500) (Two ethernet interfaces being used on this router) One for the internal wireless
network and one for the public internet access vlan. The ethernet interface connected to the public internet access vlan is going to a 4900
which has nothing but gig ports on it. So I have a 10 meg connection going to a 1 gig connection. Could this possible cause speed problems?