Cisco 4 WANs
T1, E1, T3, E3 link supports what speeds
1.544 Mb/s 2.048 Mb/s 43.7 Mb/s 35.368 Mb/s
A typical ATM line needs almost _____ percent greater bandwidth than Frame Relay to carry the same volume of network layer data.
20
ATM cells are always a fixed length of
53 bytes.
IEEE 1000BASE-LX standard supports fiber optic cable lengths of?
5KM
IEEE 1000BASE-ZX standard supports up to?
70KM
Delivers data using fixed-, 53-byte packet cells over permanent and switched virtual circuits.
ATM
Wan Devices Concentrates dialup modem, dial-in and dial-out user communications. Considered to be a legacy technology, an access server may have a mixture of analog and digital interfaces and support hundreds of simultaneous users.
Access server
-Medium-sized business - Hundreds of Employees - Serveral remote, branch, and regional offices - one central office -In-house IT staff and network support
Branch Network
Wan Devices A type of digital modem used with high-speed DSL or cable Internet service. Both operate in a similar manner to the voiceband modem, but use higher broadband frequencies and transmission speeds.
Broadband modem
Wan Devices Digital-leased lines require a CSU and a DSU. A CSU/DSU can be a separate device like a modem or it can be an interface on a router. The CSU provides termination for the digital signal and ensures connection integrity through error correction and line monitoring. The DSU converts the line frames into frames that the LAN can interpret and vice versa.
CSU/DSU
-Small-to-Medium sized business -Hundreds of employees -Multiple campus LANs -In-house IT staff and network support
Campus Network
WAN Terminology The CO is the local service provider facility or building that connects the CPE to the provider network.
Central Office (CO)
What are the two approaches to Packet Switching?
Connection-less Systems and Connection-oriented systems.
Wan Devices A router or multilayer switch that resides within the middle or backbone of the WAN, rather than at its periphery. To fulfill this role, a router or multilayer switch must be able to support multiple telecommunications interfaces of the highest speed used in the WAN core. It must also be able to forward IP packets at full speed on all of those interfaces
Core router/Multilayer switch
WAN Terminology The devices and inside wiring located on the enterprise edge connecting to a carrier link. The subscriber either owns the CPE or leases the CPE from the service provider. A subscriber, in this context, is a company that arranges for WAN services from a service provider.
Customer Premises Equipment (CPE)
Frame Relay uses identities called?
DCLI's (Data-link connection identifiers.
Wan Devices Considered to be a legacy WAN technology, a voiceband modem converts (i.e., modulates) the digital signals produced by a computer into voice frequencies that can be transmitted over the analog lines of the public telephone network. On the other side of the connection, another modem converts the sounds back into a digital signal (i.e., demodulates) for input to a computer or network connection.
Dailup Modem
Primarily provides an interface to connect subscribers to a communication link in the WAN cloud.
Data Communications Equipment
WAN Terminology Also called data circuit-terminating equipment, the DCE consists of devices that put data on the local loop. The DCE primarily provides an interface to connect subscribers to a communication link on the WAN cloud.
Data Communications Equipment (DCE)
WAN operates at what two layers of the OSI?
Data Link and Physical
A customer device that connects to the local loop through the DCE?
Data Terminal Equipment
WAN Terminology The customer devices that pass the data from a customer network or host computer for transmission over the WAN. The DTE connects to the local loop through the DCE.
Data Terminal Equipment (DTE)
The Devices owned or leased by the customer that connect to the carrier?
Demarcation Point
WAN Terminology A point established in a building or complex to separate customer equipment from service provider equipment. Physically, the demarcation point is the cabling junction box, located on the customer premises, that connects the CPE wiring to the local loop. It is usually placed for easy access by a technician. The demarcation point is the place where the responsibility for the connection changes from the user to the service provider. When problems arise, it is necessary to determine whether the user or the service provider is responsible for troubleshooting or repair.
Demarcation Point
Multiplies the amount of bandwidth that a single strand of fiber can support.
Dense wavelength division multiplexing (DWDM).
Analog telephone lines are used to provide a switched WAN connection.
Dial up
-Very Large sized Business -Thousands of employees - Home, Branch, and regional offices, teleworkers, and a central office - In-house IT staff and network support -Converged network and application services.
Distributed Network
What is the difference between Connection-less and connection-oriented systems?
Each packet carries full addressing information, making the switch evaluate the address to determine where to send the packet. The network in predetermines the route for a packet and each packet has to carry an identifier, using a temporary virtual circuit.
What are the different layer 1 connections used in WAN Services?
Electrical, Mechanical, Operational
Capabilities of DWDM?
Enables bidirectional communications over one strand of fiber. Can multiplex more than 80 different channels of data (i.e., wavelengths) onto a single fiber. Each channel is capable of carrying a 10 Gb/s multiplexed signal. Assigns incoming optical signals to specific wavelengths of light (i.e., frequencies). Can amplify these wavelengths to boost the signal strength. Supports SONET and SDH standards.
A popular replacement for traditional Frame Relay and ATM WAN access technologies.
Ethernet WAN
Includes MetroE, EoMPLS, and VPLS as WAN connection options.
Ethernet WAN
Connects multiple sites using virtual circuits and data-link connection identifies.
Frame Relay
What is an example of a connection-oriented system?
Frame Relay
What two common layer 2 protocol is used in lease lines?
HDLC or PPP
What layer 2 technologies are commonly used in WAN Services?
HDLC, PPP, Frame Relay, Ethernet WANs, MPLS, VSAT, Broadband
Converts analog to digital signals to provide a switched WAN connection over telephone lines?
ISDN
A permanent, dedicated WAN connection which uses a T- or E-carrier system.
Lease line
Considered the most expensive of all WAN access technologies.
Leased Line
The Cabling that connects the CPE to the CO?
Local Loop
WAN Terminology The actual copper or fiber cable that connects the CPE to the CO of the service provider. The local loop is also sometimes called the "last-mile".
Local Loop
Service providers and short-path labeling are used for lease lines, Ethernet WANS, and Frame Relay WANS.
MPLS
What are the two primary WAN infrastructures?
Private and Public
Wan Devices Provides internetworking and WAN access interface ports that are used to connect to the service provider network. These interfaces may be serial connections, Ethernet, or other WAN interfaces. With some types of WAN interfaces, an external device, such as a DSU/CSU or modem (analog, cable, or DSL)
Router
Service providers consist mostly of high-bandwidth fiber optic using what two standards?
SONET (American Synchronous Optical Networking) SDH (European Synchronous Digital Hierarchy)
-small-sized business - A limited number of employees - LAN focus of operations with broadband - Connectivity to the Internet - Outsourced IT support
Small Office Network
The cabling and equipment inside the WAN provider network.
Toll Network
WAN Terminology This consists of the long-haul, all-digital, fiber-optic communications lines, switches, routers, and other equipment inside the WAN provider network.
Toll network
Most WAN links are point-to-point. For this reason, the address field in the Layer 2 frame is usually not used. True or False?
True
Satellite to router communications for WAN connections.
VSAT
What WAN technology sends signals must travel approximately 35,786 kilometers?
VSAT
Wan Devices A multiport internetworking device used in service provider networks. These devices typically switch traffic, such as Frame Relay or ATM and operate at Layer 2.
WAN switch
________ are used to interconnect the enterprise LAN to remote LANs in branch sites and telecommuter sites.
WANs
The two most common types of circuit-switched WAN technologies are?
public switched telephone network (PSTN) and the Integrated Services Digital Network (ISDN).
