ADIZZYSNIPER wrote

Apex wrote Same reason why PS3s cant go on xbox LIVE

Well, not exactly the same reason. The reason why PS3's cannot get on Xbox LIVE is because Xbox and Playstation use a completely different set of online codecs, algorithms, and completely different systems. It would be like trying to run a Mac program on a Windows machine.

The real reason why they cannot connect is because Xbox LIVE is a server and PNET is a server. They are not connected in any way so they cannot access another server which they aren't connected to.
Think of it this way: Your JTAG is a computer which has one ethernet cable slot. This can only be occupied by one ethernet cable, which is obviously Xbox LIVE since a JTAG is a slightly modified Xbox console, so it can only connect to one network.
Software Development Kits can connect to PNET because they were built somewhat different than normal Xbox consoles are. They were built to debug, build, execute unsigned scripting and files, and interact with a PC while doing all the above.

Long story short: Just doesn't work like that.

you can connect a console to xlink kai, so they are capable of reaching alternative servers.. somebody with a hard working brain could probably get a jtag on pnet, but whats the point anyhow? pnet sucks