CCNA part 10, wan link-isdn

1. WAN
Wide Area Network

2. Wide Area Networks:-
• A WAN is a data communications network covering a large
geographic area.
• Unlike LANs , a WAN connection is generally rented from a service
provider.
• WANs connect various sites at different geographic locations so that
information can be exchanged.
• Factors involved in selecting a WAN technology
are:-
1. Cost
2. User needs
3. Bandwidth required.

3. Speed of WAN Links:-
• T1 = 1.544 mbps.
• T2 = 128 kbps.
• T3 = 64 kbps.
• E1 = 2mbps.

4. Types of WAN Links:-
There are three types of WAN links:-
• Dedicated (leased point-to-point) line.
• Circuit switched links.
• Packet-switched links.

5. Dedicated (leased) line:-
• Leased line are used for short-distance connections.
• For constant data flow.
• It is 100% private.
• High expensive.
• For longer connect times (always on).
Standards supported on Cisco routers
• EIA/TIA -232
• EIA/TIA -449
• V.35
• X.21
• EIA/TIA- 530

6. WAN Components
CSU/DSU
CSU/DSU
Telco
CSU/DCSSUU/DSU CSU/DSU
Telco
CSU/DSU
CPE
CSU:- channel service unit.
CPE:-customer premises equipment

7. Data link Layer Protocols:-
• WAN data-link protocols are used on serial
links to provide the basic function of data
delivery across that WAN link.
• There are two types of data-link layer
leased line protocols:-
1. HDLC (High-level Data Link Control).
2. PPP (Point-to-Point Protocol).

8. HDLC
• Vendor proprietary protocol
(Cisco).
• No support for
authentication.
• No support for compression.
• It will support synchronous
communications.
• It will not support
asynchronous
communications.
• No error correction.
PPP
• Open standard protocol.
• support for authentication
• support for compression
• It will support
synchronous
communications.
• It will support
asynchronous
communications.
• It will support error
correction, but disable by
default.

9. Circuit switched links

10. Circuit switched links:-
• It provides dedicated bandwidth between two
points, but only for the duration of the call.
• Typically used as a cheaper alternative to leased
lines, particular when connectivity in not needed
all the time.
• Also is useful for backup when a leased line or
packet-switched service fails.
• E.G. ISDN, PSTN

11. ISDN
Service
Provider
Circuit switched connections:- (ISDN)
NT1
Switch
BRI
CSU/DSU
PRI

12. ISDN
• Integrated service digital
network.
• It is a digital communication.
• It connects in fraction of
seconds.
• Speed is 128kbps.
• It support Multiple service at
a time(voice, video, data
image).
• Terminal adapter are
required.
PSTN
• Public switched telephone
network.
• It is a analog communication.
• Time to connect is high.
• Speed is up to 56 kbps(range is
33.6-56).
• One service at a time.
• Modem are required.

13. Advantages of ISDN:-
• Digital communication:-
– reliable connection
• Speed:-
– 128 kb/s (144kb/s) for BRI
– 1920 kb/s (2048 kb/s) for PRI
• Fast call setup:-
– Only 2 seconds

14. Service types:-
There are two type of services:-
1.BRI:- Basic Rate Interface
(2 B channels + 1 D channel)
B=bearer channel =64kbps.
D= delta channel = 16 kbps
2.PRI:- Primary Rate Interface
– T1 (23 B channels + 1 D channel) - 1.544 Mbps (US
standard)
– E1 (30 B channels + 2 D channel) – 2.048 Mbps
(European standard)
• B= 64 kbps
• D= 64 kbps

15. ISDN Groups & Reference Points:-
ISDN
Service
Provider
NT1
A
B
U
S/T U
ISDN
Service
Provider
Uses ISDN interference e.g. BRI
Uses S/T interference e.g. BRI

16. Reference points continue………..
ISDN
Service
Provider
TA NT1
NT2 NT1
C
D
U
U
R S/T
S T
ISDN
Service
Uses serial interference e.g. s0 Provider
Uses serial interference e.g. s0

17. Reference points:-
Reference point
• R
• S
• T
• U
• S/T
What it connect between
• TE2 & TA
• TE1 or TA & NT2
• NT2 & NT1
• NT1 & Telco
• TE1 or & NT1

18. Function Groups:-
• TE1:- (Terminal Equipment1)
1.ISDN capable four-wire cable.
2.Understands signaling and 2B+1D.
3.Uses as S reference point.e.g. bri port
• TE2:- (Terminal Equipment 2)
1.Equipment that does not understand ISDN protocol
& specification.
2.uses an R reference point, typically an RS-232 or
V.35 cable. E.g. serial port.

19. Function Groups continue………….
• TA:- (Terminal Adapter)
1.Equipment that uses R and S reference point.
2.It can be thought of as the TE1 functions group on
half of a TE2. E.g. s0
• NT1:- (Network termination type 1)
1. CPE equipment connect with U reference point.
2.Connect with T & S reference point other devices.
• NT2:- (Network termination type 2)
1.Equipment that uses a T reference point to the telco.
2.Uses an S reference point to connect to other CPE.

20. Backup lines:-
• Router to router connections
• ISDN call setup when leased line fails
Hyderabad Leased Line Dubai
ISDN
Service
Provider
ISDN Line

21. Configuration of ISDN:-
1.configure BRI interface:-
Hyderabad#config t
Hyderabad(config)#interface bri <no>
Hyderabad(config-if)#ip add negotiated
Hyderabad(config-if)# no shut
Hyderabad(config-if)#encapsulation ppp
2. Authentication configuration:-
Hyderabad(config)#ppp authentication pap chap call in
Hyderabad(config)#ppp pap sent-username <name> password <password>
Hyderabad(config)# ppp chap hostname <username>
Hyderabad(config)#ppp chap password <password>
Hyderabad(config)#exit

22. Configuration continue………….
3.Dialer command configuration:-
Hyderabad(config)#interface bri <no>
Hyderabad(config-if)# dialer string <phone. No>
Hyderabad(config-if)# dialer idle-timeout <time in sec.>
Hyderabad(config-if)#dialer-group <group no.>
Hyderabad(config-if)#exit
4. NAT commands configuration:-
Hyderabad(config)#interface e <no>
Hyderabad(config-if)# ip nat inside
Hyderabad(config-if)# interface bri <no.>
Hyderabad(config-if)#ip nat outside
Hyderabad(config-if)#exit
Hyderabad(config)#ip nat inside source list <no> interface bri
<no> overload

23. Configuration continue………….
5. Access list command configuration:-
Hyderabad(config)#access-list <acl no.> <permit/deny>
<source ip> <source wm>
Hyderabad(config)#dialer-list <dialer no.> protocol ip permit
6.Routing command configuration:-
Hyderabad(config)#ip routing
Hyderabad(config)#ip route <destination ip> <destination
wm> <exit interface type> <int no.>
7.server command:-
Hyderabad(config)#ip domain-lookup
Hyderabad(config)# ip name-server <public ip add>