WAN Connection Types

uptightexampleNetworking and Communications

Oct 24, 2013 (3 years and 11 months ago)

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WAN Networking Protocols

1

WAN Connection Types


Share bandwidth


Frame Relay and X.25


56Kbps to 2.048Mps


Point
-
to
-
Point connection


No setup before transmission


Up to 45Mbs


Setup before transmission


Dial
-
up modems or ISDN


Low bandwidth

WAN Networking Protocols

2

High
-
Level Data
-
Link Control Protocol


HDLC specifies an encapsulation method
for data on synchronous serial data links
using frame characters and checksums.


Default encapsulation used by CISCO.


Everyone has its own proprietary HDLC.


If your are connecting a CISCO router
with another type router, you must
specify an encapsulation type (protocol).

WAN Networking Protocols

3

PPP


PPP is an Internet standard protocol to provide
point
-
to
-
point, router
-
to
-
router, and host
-
to
-
host connections.


It supports network layer protocols


IP


Novell IPX


Apple Talk


It can be used over several different physical
interfaces


Asynchronous serial


ISDN synchronous serial


High
-
speed Serial Interface

WAN Networking Protocols

4

Establishing PPP Communication


Communication process is established in
three steps:


Link Establishment


Authentication


Password Authentication (PAP)


Challenge Authentication Protocol (CHAP)


Network Layer Protocol negotiation


WAN Networking Protocols

5

Link Establishment and LCP


Link Control Protocol (LCP) is responsible
to configure and test the link.


LCP packets can contain many different
pieces of information such as:


Authentication


Link Quality Monitoring and Magic Number


Compression


WAN Networking Protocols

6

Configuring PPP on Cisco Routers

WAN Networking Protocols

7

Frame Relay


Frame Relay provides connection
-
oriented, Data Link
layer communication via virtual circuits.


ANSI defines Frame Relay as a connection between the
data terminal equipment (DTE) and the data
communication equipment (DCE) over high speed digital
medium.


CSU/DSU is located at customer location and used for
encoding, filtering, and translating communication to
and from the digital line.

CSU/DSU (channel service unit/

digital service unit)

WAN Networking Protocols

8

Frame Relay


Supports many protocols, IP, Novell IPX,
Decnet, AppleTalk, ....


Efficient and fast (56Kps to 44.736Mbps)
since it does not perform error checking.


Uses both permanent virtual circuits (PVC)
and switched virtual circuits (SPC).


Virtual circuits are maintained by a
software and multiplexed on onto physical
channels.

WAN Networking Protocols

9

Data Link Connection Identifiers (DLCI)


Frame Relay virtual circuits are identified by DLCIs.


IP address need to be mapped DLCI

WAN Networking Protocols

10

How Frame Relay works

WAN Networking Protocols

11

Subinterfaces


You can have multiple virtual circuits on a
single interface and treat each one as a
separate interface.

R(config)>interface s0

R(config
-
if)>encapsulation frame
-
relay [ietf]

R(config
-
if)>int s0.16 point
-
to
-
point (or multipoint)

WAN Networking Protocols

12

Mapping Frame Relay

Manual Mapping


R(config)>interface s0

R(config
-
if)>encapsulation frame
-
relay

R(config
-
if)>int s0.16 multipoint

R(config
-
subif)>no inverse
-
arp

R(config
-
subif)>ip address 172.16.30.1 255.255.255.0

R(config
-
subif)>frame
-
relay map 172.16.30.17 16 ietf broadcast

R(config
-
subif)>frame
-
relay map 172.16.30.18 17 broadcast

R(config
-
subif)>frame
-
relay map 172.16.30.19 18


Using Reverse
-
ARP


R(config)>interface s0.16

R(config
-
subif)>encapsulation frame
-
relay ietf

R(config
-
subif)>ip address 172.16.30.1 255.255.255.0


WAN Networking Protocols

13

Integrated Services Digital Network (ISDN)


ISDN is a digital service designed to run
over existing telephone networks.


ISDN supports both voice, video, and data


Call setup is faster than with a modem.


Data rates are faster than one modem
connection.


WAN Networking Protocols

14

ISDN Components

WAN Networking Protocols

15

ISND Terminals


Terminal adapter:

A converter device that
allows non
-
ISDN devices to operate on an ISDN
network.


Terminal Equipment 1 (TE1):

A device that
supports ISDN standards.


Terminal Equipment 2 (TE2):

A non
-
ISDN
device.


Network Termination 1 (NT1):

A device that is
attached to ISND BRI lines to provide power. It
also terminates the 2
-
wire connection from CO
and connects to the 4
-
wire customer network.


Network Termination 2 (NT2):

A provider
equipment.

WAN Networking Protocols

16

Reference Points


U


The
U
-
interface

is the actual two
-
wire cable which connects
the customer’s equipment to the telecommunications provider


R


The
R
-
interface

is the wire or circuit that connects TE2 to the
TA


S


The

S
-
interface

is a four
-
wire cable from TE1 or TA to the
NT1 or NT2


T


The point between NT1 and NT2, which is also called the
T
-
interface


S/T


WAN Networking Protocols

17

Connecting to the Provider

WAN Networking Protocols

18

ISDN Switch Types


Interfaces


Basic Rate Interface (BRI)


Primary Rate (Interface)


Potential Switch Types To Be Obtained from
ISDN Providers


basic
-
5ess, basic
-
dms100, basic
-
ni,....


Service Profile Identifiers (SPIDs)


Reference number assigned to ISDN channels


Functions like a phone number


Frequently referred to as
ISDN phone numbers


Most modern ISDN systems now have a feature
called
AutoSPID


WAN Networking Protocols

19

ISDN with CISCO Router