How the Target Client is Resolved using CSIPResolvedClient

SIP Client Resolver determines the target clients by comparing the Request-URI of the incoming SIP request to the information provided in the ECOM plug-in resource file. This resource file is an XML file. All client applications using Client Resolver must be implemented as ECOM plug-ins and must have capabilities.

An application must declare capabilities, that are the supported content types and media formats that use the SIP headers and SDP m-lines. The capabilities must be declared in the code of the plug-in, in the XML file, or in the opaque_data field of the resource file.

The following is the DTD for the ECOM plug-in’s resource file:

<!-- SIP_CLIENT -->
<!ELEMENT SIP_CLIENT (SIP_HEADERS, SDP_LINES?)>

<!-- ALLOW_STARTING determines if a client can be started by the SIP stack. -->
<!ATTLIST SIP_CLIENT ALLOW_STARTING (YES|NO) #REQUIRED>

<!-- SIP_HEADERS -->
<!ELEMENT SIP_HEADERS (ACCEPT+, ALLOW_EVENTS*, ACCEPT_CONTACT*)>

<!-- ACCEPT: Accept-header as specified in RFC 3261.
  Indicates Content-Types supported by the client.
  Note that support for application/sdp must be announced as well,
  especially when the application aims to indicate capabilities based 
  on SDP. Otherwise the SDP-based rules will not be taken into account.
  An empty value means that the application is willing
  to receive SIP requests without content. 
-->
<!ELEMENT ACCEPT EMPTY>
<!ATTLIST ACCEPT value CDATA #REQUIRED>

<!-- ALLOW_EVENTS: Allow-Events-header as specified in RFC 3265
  Indicates events supported by the client.
  Compared to the event-package part of a Event-header
  in an incoming SIP request if present. 
-->
<!ELEMENT ALLOW_EVENTS EMPTY>
<!ATTLIST ALLOW_EVENTS value CDATA #REQUIRED>

<!-- ACCEPT_CONTACT: Accept-Contact-header as specified in RFC 3841
  Indicates caller preferences supported by the client.
  All the parameters must match to a Accept-Contact header 
  in an incoming SIP request if present.
-->
<!ELEMENT ACCEPT_CONTACT EMPTY>
<!ATTLIST ACCEPT_CONTACT value CDATA #REQUIRED>

<!-- SDP_LINES -->
<!ELEMENT SDP_LINES (LINE+)>

<!-- SDP Lines 
  Can be used to indicate supported media by the client.
  If defined the application must announce the capability of 
  receiving content of type application/sdp.
  Only M-line is supported currently as follows:
    - supported values of media field
    - port is rendered useless, 
          but is mandatory in M-Line's BNF (should be set to zero)
    - supported values of proto field
    - name of the application in fmt field if the
      value of media field is 'application'
  BNF for the value of the M-Line:
        media space port ["/" integer] space proto 1*(space fmt)
        media = 1*(alpha-numeric)
        port = 1*(DIGIT)
        proto = 1*(alpha-numeric)
        fmt = 1*(alpha-numeric)
    alpha-numeric = ALPHA | DIGIT
        ALPHA = "a"|"b"|"c"|"d"|"e"|"f"|"g"|"h"|"I"|"j"|"k"|
                "l"|"m"|"n"|"o "|"p"|"q"|"r"|"s"|"t"|"u"|"v"|
                "w"|"x"|"y"|"z"|"A"|"B"|"C "|"D"|"E"|"F"|"G"|
                "H"|"I"|"J"|"K"|"L"|"M"|"N"|"O"|"P"|" Q"|"R"|
                "S"|"T"|"U"|"V"|"W"|"X"|"Y"|"Z"
    DIGIT = "0"|"1"|"2"|"3"|"4"|"5"|"6"|"7"|"8"|"9"
-->
<!ELEMENT LINE EMPTY>
<!ATTLIST LINE name CDATA #REQUIRED>
<!ATTLIST LINE value CDATA #REQUIRED>

The resource (.rss) file contains the XML file and the following information:

• dll_uid and implementation_uid: These UIDs are supplied on request to Symbian Signed.

  Note: These UIDs can be the same.

• interface_uid: This must have the value 0x102010DD.

• default_data: The application UID (without 0x).

• opaque_data: The application capabilities in XML format. This field is empty if application capabilities are defined in the implementation.