602 Chapter 8: WAN Protocols and Design
Figure 8-35 outlines the process of Frame Relay initialization.
Figure 8-35
Frame Relay Initialization
HDLC
Is the IOS default. Requires a Cisco router on each end.
LAPB
Provides error recovery, but this also can result in throttling
(slowing) the data rate.
Packet Switched
Allows addition of new sites to be made quickly. Typically
involves a lower cost.
Frame Relay
Allows bursting past CIR, giving perception of free capacity.
Is pervasive in the United States.
ATM
As a WAN technology, is not as pervasively available as
Frame Relay. Offers built-in Quality of Service as its most
attractive feature.
X.25
Is available pervasively in some parts of the world. Error
recovery features are beneficial when links have higher error
rates. Typically is the third choice of these three if all are
available to all connected sites.
Table 8-45
Comparison of Leased Versus Packet Switching (Continued)
Type of WAN
Service
Data Link
Protocols
Strengths and Weaknesses
I-ARP I Am 10.1.1.2 (IP)
Status: DLCI 41 Up
Status: DLCI 41 Up
I-ARP I Am 10.1.1.1 (IP)
I-ARP I Am 10.AAAA.AAAA.AAAA (IPX)
I-ARP I Am 10.BBBB.BBBB.BBBB (IPX)
Status Enquiry
Status
Status Enquiry
Status
A
DLCI 40
B
DLCI 41
ch08.fm Page 602 Monday, March 20, 2000 5:17 PM