Routers are responsible for routing data packets
from source to destination within the LAN, and for providing
connectivity to the WAN. Within a LAN environment the router
contains broadcasts, provides local address resolution
services, such as ARP and RARP, and may segment the network
using a subnetwork structure. In order to provide these
services the router must be connected to the LAN and WAN. In
addition to determining the cable type, it is necessary to
determine whether DTE or DCE connectors are required. The DTE
is the endpoint of the user’s device on the WAN link. The DCE
is typically the point where responsibility for delivering data
passes into the hands of the service provider. When connecting
directly to a service provider, or to a device such as a
CSU/DSU that will perform signal clocking, the router is a DTE
and needs a DTE serial cable. This is typically the case for
routers. However, there are cases when the router will need to
be the DCE. When performing a back-to-back router scenario in a
test environment, one of the routers will be a DTE and the
other will be a DCE. When cabling routers for serial
connectivity, the routers will either have fixed or modular
ports. The type of port being used will affect the syntax used
later to configure each interface. Interfaces on routers with
fixed serial ports are labeled for port type and port number.
Interfaces on routers with modular serial ports are labeled for
port type, slot, and port number. The slot is the location of
the module. To configure a port on a modular card, it is
necessary to specify the interface using the syntax “port type
slot number/port number.” Use the label “serial 1/0,” when the
interface is serial, the slot number where the module is
installed is slot 1, and the port that is being referenced is
port 0. Lab Activity Lab Exercise: Connecting Router
LAN Interfaces This lab is to identify the Ethernet or Fast
Ethernet interfaces on the router. Lab Activity Lab
Exercise: Building a Basic Routed WAN This lab is to create a
simple routed WAN with two PCs, two switches or hubs, and
two
routers.
Lab Activity Lab Exercise:
Troubleshooting Interconnected Devices This lab is to create a
simple routed WAN with two PCs, two switches or hubs, and
two
routers.
Content 5.2 Cabling the
WANs 5.2.4 Routers and ISDN BRI
connections With ISDN BRI, two types of interfaces may be
used, BRI S/T and BRI U. Determine who is providing the Network
Termination 1 (NT1) device in order to determine which
interface type is needed. An NT1 is an intermediate device
located between the router and the service provider ISDN
switch. The NT1 is used to connect four-wire subscriber wiring
to the conventional two-wire local loop. In North America, the
customer typically provides the NT1, while in the rest of the
world the service provider provides the NT1 device. It may be
necessary to provide an external NT1 if the device is not
already integrated into the router. Reviewing the labeling on
the router interfaces is usually the easiest way to determine
if the router has an integrated NT1. A BRI interface with an
integrated NT1 is labeled BRI U. A BRI interface without an
integrated NT1 is labeled BRI S/T. Because routers can have
multiple ISDN interface types, determine which interface is
needed when the router is purchased. The type of BRI interface
may be determined by looking at the port label. To interconnect
the ISDN BRI port to the service-provider device, use a UTP
Category 5 straight-through cable. Caution: It is
important to insert the cable running from an ISDN BRI port
only to an ISDN jack or an ISDN switch. ISDN BRI uses voltages
that can seriously damage non-ISDN devices. Web Links
Integrated Services Digital Network (ISDN)
http://www.webwisdom.com/edu_content/ cps640fall00/lectures/
module3/WAN/sld044.htm
Content 5.2
Cabling the WANs 5.2.5 Routers and DSL
connections The Cisco 827 ADSL router has one asymmetric
digital subscriber line (ADSL) interface. To connect an ADSL
line to the ADSL port on a router, do the following:
- Connect the phone cable to the ADSL port on the router.
- Connect the other end of the phone cable to the phone
jack.
To connect a router for DSL service, use a
phone cable with RJ-11 connectors. DSL works over standard
telephone lines using pins 3 and 4 on a standard RJ-11
connector. Web Links xDSL Digital Subscriber Line
Technology http://www.webwisdom.com/edu_content/
cps640fall00/lectures/ module3/WAN/sld054.htm
Content
5.2 Cabling the WANs
5.2.6 Routers and cable connections The Cisco
uBR905 cable access router provides high-speed network access
on the cable television system to residential and small office,
home office (SOHO) subscribers. The uBR905 router has a coaxial
cable, or F-connector, interface that connects directly to the
cable system. Coaxial cable and a BNC connector are used to
connect the router and cable system. Use the following steps to
connect the Cisco uBR905 cable access router to the cable
system: - Verify that the router is not connected to
power.
- Locate the RF coaxial cable coming from the
coaxial cable (TV) wall outlet.
- Install a cable
splitter/directional coupler, if needed, to separate signals
for TV and computer use. If necessary, also install a high-pass
filter to prevent interference between the TV and computer
signals.
- Connect the coaxial cable to the F connector
of the router. Hand-tighten the connector, making sure that it
is finger-tight, and then give it a 1/6 turn with a wrench.
- Make sure that all other coaxial cable connectors,
all intermediate splitters, couplers, or ground blocks, are
securely tightened from the distribution tap to the Cisco
uBR905 router.
Caution: Do not over tighten
the connector. Over tightening may break off the connector. Do
not use a torque wrench because of the danger of tightening the
connector more than the recommended 1/6 turns after it is
finger-tight.
Content 5.2 Cabling
the WANs 5.2.7 Setting up console
connections To initially configure the Cisco device, a
management connection must be directly connected to the device.
For Cisco equipment this management attachment is called a
console port. The console port allows monitoring and
configuration of a Cisco hub, switch, or router. The cable used
between a terminal and a console port is a rollover cable, with
RJ-45 connectors. The rollover cable, also known as a console
cable, has a different pinout than the straight-through or
crossover RJ-45 cables used with Ethernet or the ISDN BRI. The
pinout for a rollover is as follows: 1 to 8
2 to 7
3
to 6
4 to 5
5 to 4
6 to 3
7 to 2
8 to
1 To set up a connection between the terminal and the Cisco
console port, perform two steps. First, connect the devices
using a rollover cable from the router console port to the
workstation serial port. An RJ-45-to-DB-9 or an RJ-45-to-DB-25
adapter may be required for the PC or terminal. Next, configure
the terminal emulation application with the following common
equipment (COM) port settings: 9600 bps, 8 data bits, no
parity, 1 stop bit, and no flow control. The AUX port is used
to provide out-of-band management through a modem. The AUX port
must be configured by way of the console port before it can be
used. The AUX port also uses the settings of 9600 bps, 8 data
bits, no parity, 1 stop bit, and no flow control. Lab
Activity Lab Exercise: Establishing a Console Connection to
a Router or Switch This lab is to create a console connection
from a PC to a router and switch using the proper cable.
Interactive Media Activity PhotoZoom: Console Cable In this
PhotoZoom, the student will view a console cable. Web
Links Applying Correct Terminal Emulator Settings for
Console Connections http://www.cisco.com/warp/public/63
/terminal_ settings.html
Content Summary An