As several of you have no doubt experienced TP-Link's adsl routers are great for the price except for the SIP- ALG issue well the new firmware updates out recently seem to finally address this issue eg:
TP-LINK TD-W8960N

1. Add supports of WEB ALG switch;
2. Add supports of 1500 Bytes MTU under PPPoA mode;
3. Fixed Chrome update issue;
4. Fixed Australia TPG PPPoE issue;
5. Fixed TCP MSS configuration issue;
6. Fixed Traffic Control needs reboot to take effect under PPPoA mode;