NGN Lab

ISCOM and FUB implemented a NGN lab reported in the figure consisting of a core and an access segment. The core consists of four IP routers Juniper M10i (Ji, i=1,…,4) and three Alcatel SR7750 routers (ALCi, i=1,…,3)) interconnected by the optical fibers contained in the Roma-Pomezia cable (50 km) [4]. As edge routers, three Cisco 3845 routers (Ci, i=1,…,3) have been deployed and interconnected to the Juniper ones. The access network consists of copper and fiber sections, even though in this paper we only refer to the FTTH solution based on the GPON.

NGN Lab
Test Bed Setup, network infrastructure at ISCOM

This network can deliver audio/video services based on IP, in unicast and multicast modality, and on DVB-T over fiber as broadcast modality.
DVB-T over fiber broadcast modality is achieved by optically converting radio frequency signal coming out from a commercial terrestrial TV antenna. TV quality perceived by the user is investigated by looking at four HD TV devices, each one located at the ONU output. Each HD TV is connected to the ONU both by means of a PC, that is used as a Set-Top-Box for IP services and by means of a commercial DVB-T Set-Top-Box, connected to the RF ONU output. It has be pointed out that the PC and the Set-Top-Box could be either a unique device or included directly in a HD TV.
One of the advantages of the multicast forwarding is the fact that the replica of the packets is carried out only at the network edge avoiding traffic jam. Multicast can be performed both at layer 3 and layer 2. We tested both the methods, even though we describe in more details the Layer 2 technique to better exploit the Carrier Ethernet trend of the next generation networks.
On test-bed network we implemented PBB-TE on Alcatel routers: in particular, we used VPLS to bring TE features in PBB, carrying out a hybrid solution consisting in the combination of Ethernet and MPLS, according to IETF draft-Balus. In this way, LAN concept is extended into MANs (Metropolitan Area Networks) and WANs (Wide Area Networks), and thanks to its inherent broadcast characteristics, Ethernet results suitable for multicast transmission of video streaming.