 8 will not be further treated (See also Chapter 11, Figure 11.8). 14.2 THE ENVIRONMENT OF THE CONTROL NETWORK The introduction of the horizontal network is performed in an environment dominated by legacy networks with numerous signalling systems, especially on the access side (See Figure 14.3). A mixture of legacy and new (SIP, H.323) signalling systems will be com- mon. This will require signalling gateways. A typical signalling gateway connects ISUP and SIP. ISUP, V5 and Q.931 will be briefly treated when describing the circuit domain. The signalling traffic should be carried in protected paths in the connectivity network. The interfaces upwards and downwards are new. ISUP, V5 and Q931 will be briefly treated when describing the circuit domain. The signalling traffic should be carried in protected paths in the connectivity network. Compare the No 7 network where the user parts are carried by the MTP carrier. The interfaces upwards and downwards 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