s are new. Media gateway control protocol (MGCP), also known as H.248 and Megaco, is the call control protocol between the MGW and the MGC (See Chapter 3). For the interface to the service network the Parlay and JAIN standards treated in chapter 3, are available. The SIP technology is also used here, for example in the interface between call control and application. The work of OMA must be considered. Access Service layer Interworking Jain, Parlay, SIP Q 931 IMS multimedia control Circuit mode Softswitch control Sigtran H. 323 Packet mode control H.323 H.248 Media gateways Figure 14.3 A typical communication environment of the control network Understanding Changing Telecommunications - Building a Successful Telecom Business 14.3 FUNDAMENTAL PLANS IN THE CONTROL NETWORK Let us start by repeating a paragraph from chapter 8, Section 8.5: 'It is also confirmed when looking at the need for information at the start of a packet communication after attaching, let us say, a mobile terminal in GPRS to a packet network. The information referred to is called PDP (packet data protocol) context. It might be a logical association between a mobile station and a public data network running across a GPRS network. The context may define aspects such as routing, QoS, security, billing, type of network, network address, access point name and radio priority. Largely, we are again back to the fundamental plans.' (See also the centre of Figure 14.4). A control layer for multimedia traffic requires a number of central functions, as opposed to the original Internet, often considered be a stupid network. A key future component is the call state/session control function/server, CSCF. The CSCF has similarities with the traffic control subsystem in ordinary tele- phone exchanges. A corresponding parallel can be found for other main traffic-handling functions. Let us look at a few FP oriented tasks performed by the CSCF: Numbering plan: Address Handling (AH). The Address Handling (AH) function handles analysis, translation, modification if req