Glossary
GL-5
User
Guide

for

the

Cisco

Application

Networking

Manager

5.2
OL-26572-01
P
PAT
Port
Address
Translation.
A

mechanism

that

allows

many
devices
on

a

LAN

to

share

one

IP

address

by
allocating
a

unique

port

address

at

Layer

4.
ping
A
common

method

for

troubleshooting

the
accessibility
of
devices.
A
ping

tests

an

ICMP

echo

message

and

its

reply.

Because

ping

is

the

simplest

test

for

a

device,

it

is
the
first

to

be

used.

If

ping

fails,

try

using

traceroute.
Run
ping

to

view

the

packets

transmitted,

packets

received,

percentage

of

packet

loss,

and

round-trip
time
in

milliseconds.
port
1.
An

i

nterface

on

an


internetworking

device

(such

as
a
router);
a

physical
entity.
2.
In

IP

terminology,

an

upper-layer

process

that

receives

information

from

lower

layers.

Ports

are
numbered,
and

each

numbered

por

t

i

s

associated

with

a

specific

process.

For

example,

SMTP

i

s
associated
with

port

25.

A

port

number

is

also

called

a

well-known

address.
3.
To

rewrite

software

or

microcode

so

that

it

will

run

on

a

different

hardware

platform

or

in

a

different
software
environment

than

that

for

which

it

was

originally

designed.
R
RAS
Registration,
Admission,

and

Status

Protocol.
Protocol
that
is
used

between
endpoints

and

the
gatekeeper
to

perform

management

functions.

RAS

signalling

function

performs

registration,
admissions,
bandwidth

changes,

st

atus,

and

disengage

procedures

between

the

VoIP

gateway

and

the
gatekeeper.
RBAC
Role-Based
Access

Control.

A

mechanism

that

allows

privileges

to

be
assigned

to

defined

roles.

The
roles
are

then

assigned

to

real

users,

allowing

or

limiting

access

to

specific

features

as

appropriate

for
each
role.
real
server
A
real

server

is

a

physical

device

assigned

to

a

server

farm.
redundancy
In
internetworking,
the

duplication

of

devices,

services,

or

connections

so

that,

in
the

event

of

a

failure,
the
redundant

devices,

services,

or

co

nnections

can

perform

the

work

of

t

hose

that

failed.
resource
class
A
defined

set

of
resources

and

allocations

available

for

use

by

a

device

(such

as

an

ACE).

Using
resource
classes

prevents

a

single

device

from

using

all

available

resources.
role
See
user
role .
RSA
Rivest,
Shamir,

and

Adelman

Signatures.

A

public-key
cryptographic
system

used

for

authentication.
RTSP
Real
Time

Streaming

Protocol.

A

client-server

multimedia

presentation

control

protocol,

designed

to
address
the

needs

for

efficient

delivery

of

streamed

multimedia

over

IP

networks.