Manufacturers different naming conventions
While SIP is an industry standard protocol, the names assigned to the configuration fields on an IP phone are far from standardised. The tables below show the text labels that you can expect to see on the web interface configuration forms next to the boxes where you must enter your settings. We show examples of the labels used for equivalent fields by four manufacturers: Snom, Aastra, Grandstream and Linksys.
There is not even agreement on what heading to show for the user account settings as a whole:
User account: Authentication Name
On SIP accounts, the authentication name and the main account ID are often identical. However, IP phones always have two different fields to allow maximum flexibility. The Grandstream and Linksys phones also have a “yes/no” or radio button to show if the authentication ID is required or is simply the same as the main account ID. The field used for the authentication name appears with the following label alongside it:
|Authentication Username||Authentication Name||Authenticate ID||Auth ID|
User account: Password
At last, some agreement! This field is called “Password” on all the different makes of phone except the Grandstream which calls it “Authenticate Password”.
User account: Main account ID
Very often, the main account ID is the same as the phone number for your IP phone. The field appears with the following label alongside it:
|Account||Phone Number||SIP User ID||User ID|
User account: SIP Registrar/SIP Domain
Absolutely no agreement here between manufacturers on what to call this. In my opinion it should be called the “SIP Domain”, but this would clearly be at odds with all the equipment manufacturers who I must assume have done their research, so I will go along with the received wisdom. It is a setting that serves two purposes – mainly it sets the SIP domain name that is used during registration and within other SIP dialogues. However, in the absence of a more explicit server identification, it can also identify the Registrar server and possibly the Proxy server where other SIP requests should be sent. The setting appears with the following labels:
|Registrar||Proxy Server||SIP Server||Proxy|
SIP Server Identification: SIP Registrar Server
It gets complicated here. First, Aastra provides an explicit field to identify the Registrar server while the others combine SIP Domain name and Registrar Server into a single field (see above). That is not altogether surprising because the IP address for the Registrar server can be resolved using DNS. However, even on those phones that do have a field for the registrar server, the “Outbound Proxy” setting overrides any IP address that can be resolved from the SIP Domain name. Confused? Yeah, me too!
SIP Server Identification: Outbound Proxy
If you set a value for the Outbound Proxy, then it will almost certainly override other SIP server identification settings in so far as all SIP requests generated by the phone get sent to the Outbound Proxy Server first. Most manufacturers use much the same label to identify this item:
|Outbound Proxy||Outbound Proxy Server||Outbound Proxy||Outbound Proxy|