Zhone IMACS 8000, Руководство пользователя

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Reference Guide 4-17
Applications PWE IP Uplink Server (8000-PWE)
4.7 PWE IP Uplink Server (8000-PWE)
The 8000-PWE card offers another new uplink card to the IMACS portfolio. The PWE card
uses PWE
3
specifications to encapsulate the traditional IMACS TDM data stream and
transport the TDM data over a packet network to the far end. The packetized data can arrive
at the far end with each node being timed off the same source (common mode clock), or the
far end system can recover the clocking by the use of an adaptive clock on the incoming packet
stream. New to the IMACS is also the ability to time the shelf from the adaptive clock source
being recovered from the incoming IP packet stream.
Customers who are used to the TDM world of stability and exceptionally low timing delay can
utilize the PWE card offering as well as continuing the use of electrical WAN facilities
concurrently with the Pseudowire streams. In this way, a customer can convert part of their
network over to the packet-based offering while maintaining a footprint into the traditional
TDM world. The IMACS accomplishes this by allowing the customer to convert individual
T1 appearances over to PWE
3
encapsulated facilities, while leaving other existing (or new)
facilities alone. By employing this method it is possible to ‘test the waters’ in the packetized
world without the need to fully convert over to it. Selected circuits can be chosen to be
transported over the newer packetized media without having to change the existing base of
clientele.