Currently using Xnet fusion naked broadband and VFX, had the VFX running fine on a Grandstream GXP-2000 IP phone, but now have a Linksys SPA2102 to try.

Network is setup as follows:

1. Dynalink RTA1320v6, configured half bridge (PPP IP extension)
2. Linksys WRT54G:
- WRT54G LAN ports:
- 1) PC
- 2) Printer
- 3) Grandstream GXP 2000 IP phone (business line)
- 4) Linksys SPA2120 (residential line)
  -- The ethernet port of WRT54G is connected to WAN port of SPA2101

I have one phone/line plugged into SPA2101.

Outgoing calls on the SPA2102 work fine.
But incoming calls do not, go to voicemail, which suggests SPA2101 might not be registering correctly?

Grandstream phone works ok for incoming/outgoing (Kiwilink VoIP).
And the Grandstream phone worked fine when configered for VFX.

Could the nested levels of router devices cause the issue? NAT?

I tried the syslog settings in the SPA2101, but couldn't receive any output (can read syslog fine with the grandstream).

Is the network layout right?
Or should the SPA2102 sit between RTA1320v6 (adsl modem) and the WRT54G?