Lab 9: Configuring HDLC ”Part I
HDLC can have many uses in the field. One instance, as mentioned previously, is to always switch the encapsulation to HDLC when testing a CSU/DSU or an internal CSU/DSU with a loopback plug. HDLC is often used when connecting to a Cisco router administered by a third party. A third-party router is a router that is not part of your autonomous system or one that is not under your direct control. HDLC provides for a quick and easy configuration, minimizing the number of problems that can go wrong because of configuration errors.
In this exercise, you are a network engineer for ACME Finance. ACME Finance is about to have a new credit card authorization center and a Wisconsin branch join the network. The credit card center, cc_center, is running HDLC protocol on a 56-kbps link to your distribution router, acme_dist. The credit card center would like to improve performance on this link as soon as possible, by using payload compression. The Wisconsin branch router, wi_branch, has a T1 leased line into acme_dist router, but it is not configured. The WAN is the first circuit in each building, and there are no users; therefore, you won't be concerned with any LAN configurations.
Configure the network as depicted in Figure 3-2.
Figure 3-2. ACME Finance Network
Use only the HDLC protocol on the serial links.
Use payload compression on the 56-kbps link between the cc_center and acme_dist routers.
Three Cisco routers. One must have two serial ports.
Four serial cables, preferably two V.35 DTE male and two V.35 DCE female cables. Otherwise, you can use the correct speed of CSU/DSUs with a crossover cable between them. When using actual CSU/DSUs, the clock rate interface command is not needed. For more information on the various ways to connect routers in a back-to-back manner, review Chapter 1, "The Key Components for Modeling an Internetwork."
Physical Layout and Prestaging