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Basic
ATM Configuration
An ATM network represents two or more routers interconnected
by ATM connections. Each router on the ATM network is connected to the ATM network
by a Virtual Channel Connection (VCC). Each router is connected to a ATM switch
that in turn connects to the ATM network. Each node on the ATM network is identified
by a unique Virtual Path Identifier (VPI) and Virtual Connection Identifier (VCI)
pair.
The interface or port used to connect the router to the ATM network
is called a ATM interface and each ATM interface must have an IP address. - Each
router is a node on the ATM network, identified by a unique VPI/VCI pair.
- The
ATM network has its own IP network number that is normally a class C or a subnet
of a class C that is unique from other subnets on the system.
- Each router
ATM interface (port) is assigned an IP address from the ATM network's subnet,
thus the netmask for each Frame interface on each router of the ATM network is
the same.
- VPI/VCI numbers are used to point from the ATM switch located
at the telephone company central office, to the PVC of a router(s) on the other
side of the ATM network.
====ETHERNET===================== 192.168.100.0/24 ===
|
| LAN IP: 192.168.100.100
+-------+--------+
| |
| Router A |
| Serial0 |
+-------+--------+
| WAN IP: 192.168.1.1
|
[-] CSU/DSU
|
|ATM WAN 192.168.1.0 255.255.255.0
+----------------------------+
| |
[-] CSU/DSU | WAN IP: 192.168.1.3
| +-------+-------+
| WAN IP: 192.168.1.2| Serial0 |
+-------+--------+ | Router C |
| Serial0 | | |
| Router B | +-------+-------+
| | | LAN IP: 192.168.300.300
+-------+--------+ ===ETHERNET======= 192.168.200.0/24===
| LAN IP: 192.168.200.200
|
====ETHERNET===================== 192.168.200.0/24 ===
Configuring
IP Over ATM The following is a sample of a port configuration:
- For this example: The ATM interface on the router is Serial0
- For
this example: The IP address of the ATM connection on the router is 192.168.1.1
!
# Comments (denoted by a hash mark at the beginning of the line)
# are permitted anywhere in the file
# See the Command Reference for more information on the
# commands below
version 2.00
!
interface Serial0
description Port 0
encapsulation atm
!
interface Serial0.1
description UUNet T1
encapsulation atm
pvc 2/33
ip address 192.168.1.1 255.255.255.0
!
ip route 0.0.0.0 0.0.0.0 Serial0.1
!
end
At this point, ATM cells should be being
transmitted and received. The status of the WAN port should change to up.
It should now be possible to ping the other side. The interface statistics (Option
2 from the Main menu) should show:
19:03:17 Interface Summary Router A
# Port Description Encaps Bandwidth HW Proto In Out
0 Ethernet0 100Mb Ethernet Ethernet 100.00 Mbit up up 0% 0%
1 Serial0 Port 0 ATM 1.54 Mbit up up 0% 0%
2 Serial0.1 UUNet T1 1.54 Mbit up up 0% 0%
----------------------------------------------------------------------------
d - Detail s - Sleep interval q - Quit
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