Which two statements are true about DPT/RPR?
A.
DPT/RPR uses a bi-directional ring consisting of two symmetric counter rotating fibre rings.
B.
DPT/RPR is defined in the IEEE 802.17 standard and it uses Token Bucket system to avoid
collisions on the fiber.
C.
DPT/RPR can be deployed in the Core of the SP networks where point-to-point POS links are
used to make best use of the Bandwidth.
D.
In DPT/RPR rings, data packets can be sent in one direction (downstream) and the
corresponding control packets in the opposite direction (upstream), thus using both fibres
concurrently to maximize bandwidth.
Explanation:
• SONET/SDH is the accepted transport architecture.
• The key building block is the twin optical fiber ring forming point-to-point connections that are
“nailed up” between several SONET/SDH add-drop multiplexers (ADM).
• The twin fiber rings in SONET/SDH ring run in parallel, one is the working ring carrying the
communication traffic. The other is the protection ring acting as a backup in the event of cable
failure or failure of an ADM node.
• SONET/SDH provides good quality performance monitoring and failure protection information
which also travel along the ring.
• The exclusive use of one ring for data and the other for protection means one ring is fully utilizedand the other ring is virtually redundant, awaiting the unlikely event of a failure.
This, of course, is not the most efficient use of fiber, especially given the considerable cost to lay
fiber.