Branch Office

1
Chapter 6

• Branch Office
• Remote Access Technologies

2
WAN Designer Considerations

• Number of users per location
• Number of simultaneous users
• Number of hours per day each user connects
• What type of access is required
• Is access required continuous or intermittent

3
Leased Lines

• Permanent telephone connection between two points
• Set up by a telecommunications carrier
• Secure private line owned exclusively by user
• Used to connect geographically distant offices
• Direction connection from network to Internet POP
• Connection fee required monthly
• Variable costs based on distance and circuit speed

4
Leased Line
5
Multidrop and Multipoint

• Multidrop allows split use of single dedicated
  line
• Corporations leverage use of leased line to many
  locations
• Several DTEs can share one line connection
• Only two DTEs can converse at one time
• Each location requires DCE for connection to
  telco
• Multipoint has several point-to-point
  connections
• Combinations are used to connect multiple sites
• Multidrop and Multipoint are integrated into
  network

6
Multidrop Connection
7
Multipoint Connection
8
Voice-Only Applications

• CSU used exclusively
• Voice calls carried between PBXs at two locations
  in same company
• Using T1 line saves long-distance charges

9
T1 Line Information

• LAN data is carried between locations
• T1 lines are connected directly to T1 CSU/DSUs
• DSU needed to convert data coming from router
• Router supports connection to LANs
• Fractal T1 service allows bandwidth/cost sharing
• Costs include distance charges from telco
• Charges based on bandwidth selected

10
T1 Voice Data
11
T1 Switched Connections
12
ISDN BRI

• Integrated Services Digital Network (ISDN)
• Provides for sending digital data on phone
  network
• Supports three concurrent separate conversations
• Basic Rate Interface (BRI)
• Supports two (B channels) to carry user traffic.
• B channel is Bearer Channel carries 64 Kbps
  each
• D Channel used for call setup/ network
  signaling 16Kbps
• Total Bandwidth 144 Kbps

13
ISDN BRI
14
NT1

• Serves as network interface for BRI connection
• Has physical/electrical termination functions for
  T1
• Requires a standard power supply source
• U-interface port used to connect to RJ-11 cable
  for phone
• Back of unit supports two S/T RJ-45 interface
  posts

15
Terminal Adapter (TA)

• Protocol converter
• Adapts equipment not designed for ISDN
• Usually a card that plugs into a PC
• External TA boxes
• Used to connect analog telephone, faxes and
  modems to an ISDN line

16
Call Routing

• Used at CO to connect local/ long-distance
  services
• All carriers granted POPs to provide long
  distance services
• Customer can choose long distance carrier to
  complete connection
• Carrier ID numbers maintained dynamically

17
ISDN PRI

• Primary Rate Interface (PRI)
• Dedicated trunks to connect corporate locations
  to CO
• Designed to support multiple individual BRI
• Internal and external voice-data communications
• United States PRI
• Total bandwidth 1.544 Mbps
• 23 (64 Kbps.) Bearer (B) channels and 1 D (64
  Kbps.) channel
• PAC RIM and European PRI
• 2,048 Mbps E1 channels
• E1channel consists of 31 B channels (64 Kbps.)
  and1 D channel (64 Kbps.)

18
ISDN PRI
19
ISDN PRI PRI-E1
20
ISDN Terminal Equipment
21
ISDN BRI NT1
22
ISDN Interfaces
23
Benefits of ISDN PRI

• Reduced call setup time
• Reduced costs
• High-speed switched access to low-volume remote
  locations
• Uses both local and interexchange carrier
  services
• Provides bandwidth on demand

24
Comparison PRI T1
25
Communication Servers

• Universally managed platforms for network
  services
• Contains communication processors software
• A communication server is a collection of
  independent servers.
• Processor cards
• Central processing unit (CPU)
• Installed memory
• Serial RS-232 port
• SNMP built in to provide remote application
  management.

26
Communication Servers (cont.)

• Controller components
• Video circuits
• Hard drives (SCSI and EIDE)
• Dual Ethernet controllers.
• Serial connections Com1, Com2 and USB

27
Communication Services
28
Multiple Operating Systems
29
Managed Internet Services
30
Racking Communication Servers

• Rack can accommodate
• Eight Celeron-based Web servers
• 24 Pentium III-based application servers
• Eight Dual SMP Pentium III-based clustered data
  resource servers can be supported in one standard
  19 rack

31
Quote of the Day

• I don't want any yes-men around me. I want
  everybody to tell me the truth even if it costs
  them their jobs.
• Samuel Goldwyn