Populus vult decipi, decipiatur. (The people want to be deceived,let them be deceived.)
Equipment that terminates T1 circuits is often designed to collect data on the performance of the link. WAN links frequently enable remote offices to connect to corporate information resources and are a necessary prerequisite to productivity. When WAN links degrade or fail, end users notice quickly and solutions must be found and implemented promptly.
Several standards address performance monitoring of T1 links. This appendix lists the most common counters that are available in end-user devices. Monitoring this data can help you spot trouble before it becomes critical, and time series data may help correlate performance issues with other network changes.
CSU/DSU functionality runs over a wide range of price points and functionality sets. Inexpensive CSU/DSUs don’t bother to collect this data at all and may not even have indicator lights for all of it. High-end CSU/DSUs may collect the data for a short time period so it is available to local network administrators. For network administrators, the best CSU/DSUs are often the integrated units sold by router vendors, because they collect performance data for long periods and expose it to network management applications by the router SNMP agent. As you read this chapter, keep in mind that not all equipment will maintain all the counters. Refer to the equipment vendor’s documentation ...