User guide

Telephony and Multimedia Services
1/1551-HSC 901 35/3 Uen C 2005-12-02
77
Increasing demands for streaming and broadcast video services in high
quality make demands on the bandwidth. In order to save bandwidth the
EDA system provides IGMP multicast for video streams in both the IP
DSLAM and the aggregation layer. Using IGMP snooping saves Ethernet
bandwidth. Requests from one end-user for video are detected by the
switch, which connects the end-user to an already active stream to another
end-user. This is illustrated in Figure 54 on page 80.
8.3.1 Quality
The EDA solution enables a multi-service access scenario in which all end-
users are able to access different services simultaneously. The Quality of
Service is ensured by Ethernet prioritization and ATM QoS mechanisms.
The Ethernet Access Domain elements conform to the IEEE 802.1Q
specification, which specifies the priority tag for video services to 5). The
upstream Ethernet traffic is tagged with the corresponding priority
information, and downstream traffic is de-tagged and mapped to a PVC
corresponding to the priority value.
The ATM QoS mechanisms are described further in section 6.3.1 on page
57.
8.3.2 Security
The recommended way for the EDA solution is to separate services using
VLAN technology as specified in IEEE 802.1Q. A VLAN for video traffic
such as TV broadcasting or pay per view can thus be created, see Figure
63 on page 102.
Other security mechanisms are described in more detail in section 9.4 on
page 88.