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20 Cards in this Set

  • Front
  • Back
What is the most important factor in chossing a WAN service?
The Cost!!

They are billed:

Flat monthly leases
What is CPE?
Customer Premises Equipment

Your network equipment:

DCE- modem, NT1 and CSU/DSU
DTE- router or access server
What is a Demarc or Demarcation Point?
This is the point where the carrier passes the link of to your site. It is also where they end their responsiblity. It can be outside or inside but it is really considered a logical boundary.
What is a local loop?
The connection from the carrier's equipment (i.e. switch) to the customer demarcation point.
What is a CO?
Central Office

This is the carrier's location. Essentially where their equipment is located.
What is the Toll Network?
The internal infrastructure for moving your traffic.
DCE connnects to what?
DCE provides what?
A termination point between two site.

It also provides clocking and synchronization to DTE.
What are the two major concerns when choosing a WAN Solution?
Cost and Type of Solution

Type of Solution is based on needs.

1. Usage
2. Bandwidth
3. Availability
4. Equipment
What are the four type of WAN connections?
1. Leased Lines- dedicated circuits
2. Circuit-switched- analog modem, ISDN
3. Packet-switched- Frame relay and X.25
4. Cell-switched- ATM and SMDS
What is a leased line?
A dedicated circuit between two sites.
What two conditions are best suited for leased-line circuits?
1. Short distance for cost-effectiveness
2. A constant stream of traffic between the two sites and having a need for guaranteed bandwidth.
What is the biggest disadvantage of leased-line connections?
The cost!! This is the most expensive of connections.
What is the difference between an asynchronous and a synchronous connection?
Synchronous connections permit simultaneous connection allow for the sending and receiving data without signalling.

Asynchronous connections are typically dial-up connection as you know modems.
What are two pieces of equipment needed if you purchase a leased line?
1. DTE device such as a router with a synchronouse serial interface. This will provide data link franing and terminate the WAN connection.

2. DCE -A CSU/DSU to terminate the connection which will provide the clocking and sychronization.
What is the CSU/DSU responible for?
1. Physical layer framing
2. Clocking
3. Synchronization
What layer of the OSI Model is a CSU/DSU?
Data Link or Layer 2
What protocol are used at the layer 2 or Data Link Layer?
What type of connection is a dial-up line?
An circuit-switch asynchronous serial connection.

What are the two types of serial connections?
Asynchronous and Synchronous

Asynchronous must wait to signal to transmit and recieve.

Synchronous can transmit and receive simultaneously.