So how is the Westall DSL modem/router connected to either computer?
This may be different for your system, but generally speaking the setup goes like the following.
You have the phone cord coming from the wall to the DSL modem/router which interprets the DSL signal and turns it into something the computer can use. You then hook the ethernet jack from this router to the WAN port on any other router, such as the WRT54G.
In your case, I would then connect the SPA to one of the normal LAN ports on the WRT54G.
So you have a setup of cord from wall --> Westell --> WRT54G --> SPA, 2400, E510
You'll have to work with your ISP to make sure the WRT54G and Westell are communicating properly. Generally I would just recommend putting the Westell into bridged mode, and doing a PPPoE connection with the WRT54G, but this might be a bit much to tackle at the moment. First just try and get something working, write down all the settings and anything else you'd need to recreate this, and then you can start looking into setting up a bridged connection.
And on a somewhat unrelated note, it would be quite behooving of you to update both systems to SP3 if they're both going to be connected to the Internet.
We now have 2 home PCs--one Dell Dimension 2400 with Windows XP, Service Pack 2, 2.2 Ghz Intel Pentium 4, 40 GB hard drive, 1022 Mb memory, Broadcom 440x 10/100 Integrated Controller
and one Dell Dimension E510 with Windows XP, Service Pack 2, 2.8 Ghz Intel Pentium 4, 160 Gb hard drive, 512 Mb memory, Integrated 10/100 Network card
Through our one ISP, we have VoIP and DSL, with a Linksys SPA 2010 phone adapter with router and a Westell 6100 router (both from ISP, and installed via the Dimension 2400, which I'd like to continue using as host computer).
I want to network the 2 computers for Internet use, so I bought a Linksys WRT54G. I put in the WRT54G installation CD, then everything got confusing. The SPA 2010 has one Ethernet port with cable to the Network connection port in the computer. The SPA 2010 has the Internet port connected by cable to the Ethernet port of the Westell. The SPA 2010 hasPhone1 port with phone wire to baseboard jack. The Westell has only one Ethernet port connected to the SPA as already mentioned. The DSL port of the Westell is connected by a thin wire to another baseboard jack. I'm confused, because I cannot figure (1).how to set the WRT54G up, even after trial and error by changing cable positions with the 3 routers.Have read extensively on Internet but there is no clear answer. Also, (2).do I have to get wireless adapters (as neither computer has a wireless adapter)?
Please advise. Thank you. Computers are within 25 feet of each other, in adjoining upstairs rooms.