That's a very strange local IP
Bring wrote:arp commands are not good, try removing lvi from pi and phone line from dell modem, reboot pi and see if arp commands are still present. If they are try your most powerful usb power supply on the pi and check again.
ARP command is fine, he's actually completely wrong about that. It always ARPs .99 by default, and after the Dreamcast connects it dedicates .98
Usually if it won't dial it's usually because
A.) The Pi can't obtain an IP address
B.) The modem isn't compatible
C.) The voltage is bad
If you're using internet from a public place like a college or apartment complex (judging from the strange IP) then the Pi might not have permissions to reserve an IP address for the incoming Dreamcast connection
We don't really have enough info to help you, and the picture of the modem lights is blurry, can't see if both lights are on or not
Load up Planetweb, go to settings --> optional settings --> Enable Verbose Modem Messages --> test dial and post screenshots of the errors. It will say "No dial tone"/"No carrier"/etc