Switch User's Manual

Navigation 27

Differentiated Services Code Point (DSCP)

The first six bits of the DS field. The DSCP uses

packet marking to guarantee a fixed percentage

of total bandwidth to each of several applications

(guarantees Quality of Service).

digital subscriber line (DSL)

In Integrated Services Digital Networks (ISDN),

equipment that provides full-duplex service on

a single twisted metallic pair at a rate sufficient

to support ISDN basic access and additional

framing, timing recovery, and operational

functions.

digital subscriber line access multiplexer (DSLAM)

A network device, at a telephone company

central office, that receives signals from

multiple customer digital subscriber line (DSL)

connections and uses multiplexing techniques to

place the signals on a high-speed backbone line.

Dual port controller (DPC)

A Field Programmable Gate Array (FPGA)

device on the R module.

dispersion

The broadening of input pulses as they travel the

length of an optical fiber. The following types of

dispersion exist:

• modal dispersion-caused by the many optical

path lengths in a multimode fiber

•

chromatic dispersion-caused by the

differential delay at various wavelengths in an

optical fiber

• waveguide dispersion-caused by light

traveling through both the core and cladding

materials in single-mode fibers

Distance Vector Multicast Routing Protocol (DVMRP)

A dense mode routing protocol that floods

multicast data to all internetwork routers.

Nortel Ethernet Routing Switch 8600

Terminology

NN46205-102 01.01 Standard

30 May 2008