5.

[ S N O M 4 S N A T F I L T E R ]

5.1 Interface to the Web Server

The interface to the web server is built upon http. The communi- cation is a request/response protocol. The SBC requests information from the application server, and the application server answers. The reverse communication direction is neither possible not necessary.

All requests are formulated as GET requests. The parameters are URL-encoded. The typical request has the form:

GET /post.htm?action=register&from=123@test.com HTTP/1.1 Host: test.com:8181

Accept-Language: en-us

Connection: Keep-Alive

Keep-Alive: 5

User-Agent: Mozilla/4.0 (compatible; snom)

The responses contain the answer in the body. The SBC checks the response code, and if the code is 2xx, it processes the attachment.

The attachment is encoded using a simple line-based protocol.

From: „Albert Einstein“ <sip:albert@einstein>

To: „Isaac Newton“ <sip:isaac@newton>

The name of the header is printed before a colon. It is not case sensitive. The argument follows the colon. If there is white space before or at the end, this white space is stripped. Therefore, the two headers are equivalent:

From: „Albert Einstein“ <sip:albert@einstein> from:“Albert Einstein“ <sip:albert@einstein>

Note that the white space inside the argument is not changed.

The SBC uses only http (TCP), a secure transport layer is not supported. Also, UDP or other transport layers are not supported. The current version opens a new TCP connection for every request. This may be optimized in future versions.

5.2 Authentication

If the Http URL for registration is set in the system settings, the SBC performs the following algorithm for every request:

52 • Web Server Integration

Page 52
Image 52
Snom 4S manual Interface to the Web Server, Authentication