contains up to eight signalling routes. Each signalling route in a route set is given a priority. The signalling route with the highest priority is used while signalling routes with a lower priority will be used only when the primary route is out of use. The signalling load may be shared between several routes with the same priority. Narrowband SS7 components are defined and used on TDM interfaces (i.e. A interface and PLMN/PSTN interfaces). Broadband SS7 Signalling The broadband SS7 protocol stack is used on the Iu-CS interface, i.e. between RNC and MGW. Broadband SS7 is needed to enable transmission of mobile specific protocols like RANAP over the ATM. The ATM based signalling links are based on the ATM adaptation layer 5 (AAL5) VPI-VCI channels. The user and application part protocols of the SS7 protocol stack (e.g. TCAP, SCCP, MAP, INAP/CAP, RANAP, etc.) require broadband adaptations to be carried over the ATM network. The main difference to the upper layers is the longer 4 kbytes maximum message length. The SCCP needs small modifications to SCCP level message segmentation. MTP level 3 functionality changes are also minor. These are specified in ITU-T Recommendation Q.2210. The MTP level 2 will be replaced by two new protocols, the Service Specific Connection Oriented Protocol (SSCOP) and the Service Specific Coordination Function (SSCF)-NNI. The SSCOP is a new fast data transfer protocol designed for high speed networks. The SSCF-NNI provides adaptation between the SSCOP and MTP-3. The broadband SS7 link consists of a single ATM link between two signalling points on the same signalling network. The signalling link is based on the AAL5 channel created on a VPI-VCI. To create an ATM signalling link set: create ATM termination points; create a signalling channel VPI-VCI; Core Network Planning and Optimisation create signalling links using a created signalling channel; create an SS7 signalling link set; create a signalling route set; activate the MTP configuration; create the SCCP configuration; activate the SCC