2002 - cesnet

The existing logical topology of multicast is not congruent (unicast is transmittedthrough MPLS, multicast without MPLS tags). In the future, we plan to verifythe characteristics of multicast MPLS VPN, which are currently implemented inexperimental versions of the router operating system (IOS).3.4 Planned Changes in BackboneNetwork Topology and ServicesThe stabilisation of the backbone network and the deployment of the ring topologydid not solve the remaining problems and missing features and services,which we had planned before. This is why we carried out an evaluation of theexisting situation and possibilities for further solutions. During the first half of2003, we plan the following fundamental changes in the backbone network architectureand services:• Redundant backbone network– Distribution of foreign connectivity among various external borderrouters (Internet, Internet backup, GÉANT)– Double access to NIX.CZ (Gigabit Ethernet anticipated)– Double connection of all GigaPoPs in the backbone network throughcircuits with corresponding capacities• Adjustment of the redundancy to new topology– Establishment of basic backbone rings– Termination of each ring in different backbone core devices (two centralP routers in GigaPoP Prague)• Changes in the topology of GigaPoP– Distribution of logical functions to various devices within GigaPoP (Pand PE routers)– Connection of P and PE routers with a sufficient capacity (2 Gbps ormore), depending on the necessary access capacity in GigaPoP– Implementation of MPLS VPN– Support of QoS, CoS, ACL at the input of the backbone network– Native distribution of IPv6– Multicast distributionAs regards the division of functions and management of network devices, thegeneral topology of GigaPoP (Figure 3.5) is based on the following:• Core backbone– Including P routers of the MPLS core, in which backbone lines areterminated,– Under the central management.High-speed National Research Network and its New Applications 200223