Assume 20 bytes of voice payload, 6 bytes for the Layer 2 header, 1 byte for the end-of-frame flag,
and the IP, UDP, and RTP headers are compressed to 2 bytes, how much bandwidth should be
allocated to the strict priority queue for six VoIP calls that use a G.729 codec over a multilink PPP link
with cRTP enabled?

A.
80.4 kb/s

B.
91.2 kb/s

C.
78.4 kb/s

D.
69.6 kb/s

E.
62.4 kb/s

Explanation:
Voice payloads are encapsulated by RTP, then by UDP, then by IP. A Layer 2 header of the correct
format is applied; the type obviously depends on the link technology in use by each router interface:
A single voice call generates two one-way RTP/UDP/IP packet streams. UDP provides multiplexing

and checksum capability; RTP provides payload identification, timestamps, and sequence
numbering.