Telecom Chapter 10 - Carrier Wide Area Networks (WANs)

Traffic Shaping

A QoS mechanism that introduces some amount of delay in traffic that exceeds an administratively defined rate.

Carrier Ethernet

A WAN technology that sends Ethernet traffic across long-distance WAN connections. Benefits: cost, familiarity, speed, speed agility, QoS, and security.

Leased Line

A serial communications circuit between two points, provided by some service provider, typically a telephone company. Because the telco does not sell a physical cable between the two endpoints, instead charging a monthly fee for the ability to send bits between the two sites, the service is considered to be a leased service. Fast, point-to-point, always-on connections.

Multi-Protocol Label Switching (MPLS)

Ability to control the direction path that it takes across a leased line. Label switched routers (LSR). Increased cost, but more control and does not use the internet

Fiber to the Home (FTTH)

An up-and-coming technology that promises even higher speeds than DSL which provides a direct fiber optic connection to homes.

Channel Reuse

Answer to the question: why cells? The number of channels permitted by regulators is limited and subscriber demand is heavy.

WAN Optimization

Compression Caching Traffic Shaping

reducing redundancy in the data

Compression reduces traffic by ________.

Wide Area Network (WAN)

Connect different sites within an organization or between organizations. Managed by a carrier. 3 basic components: - Customer Premises Equipment (CPE), like a mobile device or desktop computer, whatever is in your premises. - Access Links connect the CPE to the network core of the WAN. - Network Core connects access links to other access links.

What are the two purposes for carrier WANs?

Connect sites with a customer corporation. Connect customer sites to the internet.

Cellsite

Contains a transceiver (transmitter/receiver) to receive mobile phone signals and to send signals out to mobile phones.

both voice transmission and data transmission

DSL offers ________.

3G

Decent data transmission for Web surfing began with ________ technology.

E-LAN Service

Extends the LAN to the wide area.

Cable Modems

For cable modem service, customers need ________.

Coaxial Cables

For their transmission medium, cable television companies primarily use ________.

both It is offered by carriers instead of being installed and managed by the company using it and It is for MAN and WAN services

How does carrier Ethernet differ from traditional Ethernet?

Handoff

If a subscriber moves from one cell to another within a city, the MTSO (mobile telephone switching office) will implement a _____ from one cellsite to another.

E-LAN Service

In Carrier Ethernet, which connects multiple distant sites into a single Ethernet network?

first label-switching router

In MPLS, the ________ adds the label to the packet. MPLS is most expensive.

Economic reasons

LAN speeds are faster than WAN speeds because of ________.

either single networks or local internets

LANs are ________.

Digital Subscriber Line (DSL)

Line between end office switch and the customer when a telephone company transmits digital signals over it.

Label Number

MPLS routers base their decisions on a packet's ________.

Asymmetric Digital Subscriber Line (ADSL)

Provides simultaneous voice and data to residential customers. Residential customers must have ____ modems and splitters that separate voice and data.

Multiprotocol Label Switching (MPLS)

Reduces cost per packet handled because there is no need to go through the routing table process. However, increases cost because companies use it to engineer and manage their IP networks more effectively, including imposing QoS guarantees. Overall, much more expensive that plain IP. Companies use it for intra-site traffic because they need excellent QoS for critical corporate applications.

E-Line Service

Site-to-site service. Competes directly with leased lines but handles frame formatting and other Layer 2 functionality.

Caching

The local storage of frequently needed files that would otherwise be obtained from an external source.

Higher Speed

The promise of Fiber to the Home is ________.

both preventing certain undesirable traffic from entering the network and limiting the amount of certain undesirable traffic entering the network

Traffic shaping reduces traffic by ________.

data

Two-way amplifiers are needed for cable ________ service.

One-pair voice-grade (1PVG) UTP

What telephone companies traditionally serve residential customers. A single unshielded pair created for voice, not data.

One-Pair Voice-Grade UTP

What transmission medium do ALL DSL services use?

1-pair VG UTP

Which of the following already runs to nearly all customer premises?