As an example, if a customer is
Application Steer Wrap
Speed Slower (signaling) Faster (local)
Packet loss Higher Lower
Delay Lower Higher
Bandwidth effi ciency (for BE) Higher Lower
Reordering (after recovery) Lower Higher
Support multicast traffi c Complex Simple
Implementation Client MAC
TABLE 12.3 Wrap and Steer Restoration Characteristics
358 Chapter 12
receiving a 20 Mbps Ethernet service and desires protection in the event of an outage
there are three options available. These are: (a) restore the entire 20 mbps service,
(b) do not restore any service and (c) partially restore the service i.e., default to some
number of mbps lower than 20 mbps during the protection event.
QoS
Another important aspect of 802.17 for video and voice services is the ability of the RPR
MAC to signal to every other node on the ring the state of its links and the available
bandwidth on all network segments. As noted above transit queues allow traffic to
pass right through a node without queuing or inspection beyond the RPR header. This
ensures that there is no delay or delay variation for this high priority traffic. Since the
802.17 MAC can automatically control these variables it is ideally suited to carry video
and voice; both of which are subject to interference from latency and jitter.
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