 What we have understood so far is that coaxial cable is very important. It is a medium that has been there in Technically advanced countries That is the developed world for quite much time and for us as a developing nation in Pakistan as well. So one wonders if other than internet connectivity and voice and Of course television what all other services could be provided on the existing infrastructure for that the cable labs has done a tremendous work in X in widening and extending the scope that they call as the packet cable So it is the coaxial cable can carry literally any packet no matter what payload it carries So we'd look at the primary motivation of packet cable architecture and we'd look at the specifications which allow us to incorporate new and emerging services even for NGNs on existing Cable network and we'll briefly look at some of the features which are already there which give us an insight into How new services can be incorporated? so essentially packet cable specifications is a mechanism to look at the existing cable network access architecture as a Super network that is a network that literally provides Communication mechanism between any kind of network on This existing cop coaxial cable Although the primary motivation the primary motivation for the coaxial cable was voice communication Internet connectivity, but later as we saw in dox's up to 3.0 The quality of service based multimedia content delivery started becoming more of a necessity So the packet cable specifications allows all the important details including the interfaces the message format the exchange of packets for establishing the signaling whether in-band or out-of-band and Interoperability amongst a variety of services because all these services have to Rely on one common medium. So there should not be any conflict any Contradiction or any dish harmony between these services So packet cable specifications actually deal with voice video broadband multimedia services for Defining how these Services can be executed or delivered on top of dox's because if you remember the end-to-end diagram we had the dox's scope Which was between the cable modem and the cable modem termination system. That was the scope of dox's So it means a dox's encapsulated packet is now to be carried to its destined Service provider network. So that is the scope of packet cable So packet cable talks about or specifies The features which encompass but certainly are not limited to how call signal signaling takes place So this is related to voice over IP. It means a packet that Starts its journey from the cable modem to the cable modem termination service to the Aggregation network finally has to land into maybe a PSTN network or a PLMN network that is The mobile network. So it means the signaling has to take place Now an interesting thing is we are talking about sending traffic from a packet eyes Do a packetizing device a cable modem that enters into a SS7 network that is the signaling standard 7 which is the out of band signaling network architecture for For voice so call signaling has to it has to encompass every such thing then Accounting including the triple a which is implemented through radius and Diameter if you recall then configuration management the device a discovery Software upgradation Security policy enforcement And then as I already said the interfacing between the existing Non-IP circuit switched PSTN network and To top it all the features all these features have to incorporate the prioritizing of traffic because Unless the traffic Can be classified according to certain QS requirements all these different Service provider networks would not be able to offer their services Simultaneously on on the cable access network. So now this is what the big picture looks like here. You can see we have IP based network that is the internet. We have the PSTN PLMN ISDN we have the Toxis network as such that is the network behind which the cable modems are Accessing the packet cable network through their respective cable modems and then we have the Integration of all these into the IP cloud You can see that I would say if you look at it from the left-hand side That is the residential side or the corporate User side the right-hand side is the destination side in order to Establish all these services over this kind of network arrangement Then certain additional Services are also be required which are not data services as such but are the management Applications including the application manager application server the media gateway signaling gateway that is the media and signaling gateway Convert the packet based in band signaling into explicit SS7 based out of band signaling then we also have the home subscriber server that acts like HLR VLR and then we have the IP multimedia system. It allows the transfer of multiple types of Traffic that is multimedia traffic on any network. So in fact IP multimedia subsystem home subscriber server Application manager and application servers are not exactly part of cable network architecture These would be present in any network that is going to talk to legacy PSTNs PLMNs ISTN networks and the internet. So it means if every network needs that so does The packet cable network architecture as well