Manipulation and routing rules can be combined with one another. You can basically specify whether first the routing and then the manipulation rules are executed, or the converse. Furthermore, the order of the rules within these units can be defined by arranging the rules in the table accordingly (from top to bottom).

The manipulations configured with an INI file, which manipulate the (SIP) CallControl messages themselves, are an exception. These always take precedence over the routing rules.

While SwyxConnect is subdivided into its functional units (gateway and SAS application), the units are also listed according to the call flow of the CallControl messages (Fig. C-2: Functionality of manipulation rules). This is a scenario, in which SAS is active, i.e. the IP route to SwyxWare is interrupted. An incoming call from the PSTN is transferred via the gateway application to the SAS application and from there in turn via the gateway application to an ISDN telephone, which is connected to a trunk of SwyxConnect.

The call directions are shown in the upper area of the illustration. The part of the call from the gateway application to the SAS application is a Tel-to-IP call. The SIP message received from the IP network to the SAS application belongs to the IP-to-IP category. The part of the call from the SAS application to the gateway application is an IP-to-Tel call.

The lower area shows the points where the manipulation rules take effect. The gateway outbound manipulations are applied as a SIP message leaves the gateway in the direction IP. The gateway inbound manipulations are applied to the SIP messages that are sent to the gateway from the IP side. On the same principle, the SAS inbound manipulation rules are applied to the SIP messages that are transferred from the IP side to the SAS application.