Odd disconnect?

[dswartz]

No. To clarify: the UAC (client, ATA, whatever) apparently needs to support RFC4028. The GS doesn't. To the best of our knowledge, the PAP2 doesn't. Asterisk prior to release 1.6 doesn't.

[voxabox]

No. To clarify: the UAC (client, ATA, whatever) apparently needs to support RFC4028. The GS doesn't. To the best of our knowledge, the PAP2 doesn't. Asterisk prior to release 1.6 doesn't.

I beg to differ
in the User Manual for HandyTone-286 Rev 3.0, section 4.1

4.1 Key Features
• Support SIP Session Timer

there's more info about session timer settings on p32-p33 of the same doc