Download Network Troubleshooting

SECTION II
TROUBLESHOOTING LOCAL-AREA NETWORKS
394
10.2
ATM
10
Troubleshooting ATM
In addition to protocol analyzers and cable testers for twisted pair and fiber
optics, troubleshooting in ATM networks involves the use of ATM switch and
node management software that is able to track and display the various ATM
Operations and Maintenance (OAM) information flows.
ATM contains a number of powerful OAM functions. Because ATM is based on a
switched architecture, these integrated monitoring functions are very important; it is no longer possible to monitor the entire activity in a network from
a single point, as in traditional network technologies such as Ethernet, Token
Ring or FDDI. Monitoring of a single ATM connection only yields information
about the traffic between the two connection endpoints (such as a computer
system and an ATM switch port). The first step in diagnosing problems in an
ATM network is to monitor and analyze data obtained from operation logs and
OAM statistics of the various ATM network nodes. Although many of today’s
ATM components only support, interpret, or display a small proportion of the
ATM diagnostics functions, a protocol analyzer can be used to analyze all five
OAM flows (F1–F5) and determine whether they report a problem or not.
Figure 10.59 F1–F3 OAM flow statistics with the Agilent Technologies Advisor ATM