Welltech ePBX80 V.1.1 - Manual (Page 62)

Welltech Technology Co., Ltd. 62
IP Address/DNS Enter IP address or domain name of ITSP server.
Port Port number of remote ITSP server or IP-PBX for registering.
SIP Domain You can insert the SIP Domain here if it is necessary. Some
SIP platform may verify incoming correct SIP Domain which
was located in the
From header of SIP protocol. Modify this field
let ePBX80 register to SIP Trunk successfully.
Realm Realm configuration of ITSP SIP Server or another ePBX80 or
IP-PBX.
Note:
 When a call was initiated from ePBX80 to a remote SIP
Trunk, the remote SIP Server or IP-PBX may attempt to
authenticate this Call for security consideration. ePBX80
should reply correct Account ID and Password to remote
Server or IP-PBX. How does ePBX80 know which ID and
Password it should send? When the call is going to SIP
Trunk via ePBX80, the remote SIP Server or IP-PBX may
reply a 407 code (SIP protocol format) to ePBX80, which
contains a parameter called “Realm” for authentication.
ePBX80 will re-sent this call and contains correct ID and
Password based on the Realm which was configured here.
The Realm should be unique. For more information
about Realm, please contact with your ITSP Service
provider’s or remote SIP Server technician.
 If you have multiple ePBX80s to connect in a group, you
may want those ePBX80s to call each other. You should set
up the Extension to let those ePBX80 can register to each
other (other IP-PBX), and you should configure unique
[Realm] in the webpage of Configuration IP PBX.
Status Once SIP Trunk is configured and enabled, here will show the
registration status.
Apply Click Apply button to save your customized settings and exit
this screen.
Cancel Click Cancel button to exit this screen without saving.