Problem receiving calls on linksys/sipura hardphones

I have created a ring-call extension:

exten => 100,1,Dial(SIP/zoiper_x250&SIP/xlite_x250&SIP/bria_note3&SIP/monika_gigaset&SIP/fritzbox_master&SIP/cisco_sportroom&SIP/onda_kitchen&SIP/tablet_livingroom&SIP/chiara_samsung&SIP/chiara_ipad&SIP/laura_ipad, 30) ; ext 100: all localsets are called simultaneuously

This works fine if the call is picked up by softphones or by fritzbox-phones. If I let a Linksys/Sipura SP-901 pick it up, however, the caller will not hear anything and the call will be dropped. Any suggestions? The same SP-901 works fine if registered directly with the SIP provider rather than with the asterisk server (which is hooked up to the same SIP provider).

Please provide protocol logs

– SIP/cisco_kitchen-0000003e answered SIP/sipcall_2626248-0000003b
– Channel SIP/cisco_kitchen-0000003e joined ‘simple_bridge’ basic-bridge
– Channel SIP/sipcall_2626248-0000003b joined ‘simple_bridge’ basic-bridge
> Bridge a785d733-c45d-4e4e-ba72-4c922023f97f: switching from simple_bridge technology to native_rtp
> Remotely bridged ‘SIP/sipcall_2626248-0000003b’ and ‘SIP/cisco_kitchen-0000003e’ - media will flow directly between them
> Remotely bridged ‘SIP/sipcall_2626248-0000003b’ and ‘SIP/cisco_kitchen-0000003e’ - media will flow directly between them
[Jun 8 12:53:33] WARNING[23286][C-0000001c]: chan_sip.c:16571 __set_address_from_contact: Invalid contact uri (missing sip: or sips:)
[Jun 8 12:53:33] WARNING[23286][C-0000001c]: chan_sip.c:16584 __set_address_from_contact: Invalid URI: parse_uri failed to acquire hos
– Channel SIP/sipcall_2626248-0000003b left ‘native_rtp’ basic-bridge
== Spawn extension (LocalSets, 100, 1) exited non-zero on ‘SIP/sipcall_2626248-0000003b’
– Executing [h@LocalSets:1] Verbose(“SIP/sipcall_2626248-0000003b”, “0,“hangup processing””) in new stack
"hangup processing"
– Channel SIP/cisco_kitchen-0000003e left ‘native_rtp’ basic-bridge
– Executing [h@LocalSets:2] System(“SIP/sipcall_2626248-0000003b”, "echo -e “Asterisk incoming call. \n Duration: 0 seconds.\n Cal869 \n Destination: 100 \n Destination context: LocalSets \n Channel name: SIP/sipcall_2626248-0000003b \n Destination channel: SIP/tabuments: SIP/zoiper_x250&SIP/xlite_x250&SIP/bria_note3&SIP/monika_gigaset&SIP/fritzbox_master&SIP/cisco_kitchen&SIP/cisco_livingroom&SIPamsung&SIP/chiara_ipad&SIP/laura_ipad, 30 \n Time the call started.: 2016-06-08 12:53:11 \n Time the call was answered.: \n Time the ction of the call once it was answered.: 0 \n Result: NO ANSWER \n DOCUMENTATION, BILL, IGNORE etc: DOCUMENTATION \n The channel’s accou42552869) called on: Wednesday 08.06.2016 at 12:53:33’”) in new stack
– Executing [h@LocalSets:3] Verbose(“SIP/sipcall_2626248-0000003b”, “0,Call Termination at Wed Jun 8 12:53:33 2016”) in new stack
Call Termination at Wed Jun 8 12:53:33 2016

That’s not the protocol trace. You want sip set debug on. However it does show that there has been a protocol violation by the other side.