Foundation Summary 629
Foundation Summary
This section is a collection of tables that provide a convenient review of many key concepts in
this chapter. If you are already comfortable with the topics in this chapter, this summary could
help you recall a few details. If you who have just read this chapter, this review should help
solidify some key facts. If you are doing your final preparation before the exam, Tables 16-5
through 16-7 are a convenient way to review the day before the exam.
Serialization delay is especially a problem on low-speed links. Table 16-7 shows the
relationship between link speed and frame size. Note that a 1 KB frame requires 144 ms on
a 56 Kbps circuit. The delay for that circuit, in and of itself, exceeds the target delay budget
of 150 ms.
Table 16-5
Voice Network Recommendations
Location
Recommended Equipment
Wiring closet
Catalyst 2900 XL
Catalyst 4000
Cisco 2600, 3810
Backbone
Catalyst 6500
Catalyst 8500
Cisco 3600, 7200
WAN edge
Cisco Routers 7200, 7500
Catalyst 5500
Catalyst 8500
Table 16-6
ISO Reference Model and H.323 Standards
OSI Protocol Layer
ITU H.323 Standard
Application
E.164 phone number
Presentation
G.711, G.729, G.729a, and so on
Session
H.323, H.245, H.225, RTCP
Transport
RTP, UDP
Network
IP, RSVP, WFQ
Data Link
PPP, Frame, ATM
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