SIP ALG disabled on the customers router
Check SIP trunk credentials using a soft phone app, this will save a lot of time.
SV9100:
SL2100:
Note: for the SV2100 VOIPDB is only required if you need to exceed 8 VoIP channels
System Programming:
Check for enough VoIP resources ( 1 per trunk for Non IP terminal systems, 2 per trunk for IP terminal systems.
PRG 10-12-09 Valid IP address on the customers network
RRG 10-12-10 Subnet mask that matches the customers network
PRG 84-26-01 Valid IP address on the customers network ( by convention, one IP above 10-12-09 )
PRG 10-68-01 SIP trunk Type / Start port & number of ports
Be careful this doesn’t conflict with any COT / ISDN trunk cards
10-67-01 Turn DNS mode on
10-67-02 enter a valid DNS server
10-28-01 Domain name eg a4uc.com.au
10-28-02 Host name eg encreg
( 01&02 together build a FQDN ) encreg.a4uc.com.au
10-28-05 Domain Assignment Domain Name
10-29-01 Outbound default proxy Enable
10-29-05 Register Mode Manual
10-29-11 Registrar Domain Name eg enreg.a4uc.com.au
10-29-12 Proxy Domain Name eg a4uc.com.au
10-29-13 Proxy Host Name eg enreg
( 12&13 together build a FQDN ) encreg.a4uc.com.au
10-29-14 SIP Carrier Choice Use “G”
10-29-16 Sub Register Mode Disable
Now for the TLS part:
SIP packets 10-28-03 Transport Protocol = TLS
RTP packets 84-27-03 SRTP Mode = enable