As wireless LANs continue to permeate the entire network infrastructure from the SOHO to the enterprise, it's clear that traditional wired LANs need to connect with them. But to what degree?
This question came to the forefront in our recent testing of a router designed for small businesses and home offices, an Intertex IX66 SIP-capable device. (We'll get to the Session Initiation Protocol capabilities in a later newsletter.) The device is a step beyond your typical mass-marketed SOHO router in both SIP capabilities and firewall capabilities. It also has significantly more configuration options.
One of the options that was most interesting - and that consequently started this discussion - was whether the wireless connections should be part of the same set of Class-C IP addresses as the wired connections.
For SOHO products, which often become part of an SMB network as well, it's a given that they are on the same private Class-C net. For instance, all devices might be assigned an IP address in the 192.168.1.xxx range. This allows for seamless networking with Windows-based file and printer sharing, plus the use of network-attached printers.
In the case of the Intertex unit, the wireless capabilities are added by use of a "feature slot" where an 802.11b compact flash card can be inserted. In the default configuration, the WLAN connections are assigned different private IP addresses on a different Class-C net than addresses on the wired LAN. For instance, the wired connections might use 192.168.1.xxx addresses while the wireless addresses are 182.168.2.xxx. Both wireless and wired devices have the capability to connect to the Internet through the router, but to connect to each other they have to traverse the internal router function.