Assume 6 bytes for the Layer 2 header, 1 byte for the end-of-frame flag, and a 40-millisecond
voice payload, how much bandwidth should be allocated to the strict priority queue for five VoIP
calls that use a G.729 codec over a multilink PPP link?
A.
87 kb/s
B.
134 kb/s
C.
102.6 kb/s
D.
77.6 kb/s
E.
71.3 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.