next up previous
Next: dedicated studies of Up: recommendations Previous: existing work

switched environments

In switched environments, where there is no IP layer information, the above statistics are not completely applicable. Without demand from their customer base, many switch vendors have put statistics at a second priority since it tends to detract from forwarding performance anyway. Some ATM switches can collect per-VC (virtual circuit) statistics such as those described in the ATM MIB [23].

One alternative for providers that support IP over an internal ATM infrastructure is to collect the IP statistics described above, and in fact use objects such as host-host matrices to plan what number and quality of ATM virtual circuits might be necessary to support the IP traffic workload. For switched FDDI environments, the provider could collect statistics on each LAN coming into the switch, and collapse it during analysis to determine possible compound effects within the switch. in addition segmenting traffic by interface, customer, and perhaps by protocol/application. If there is no access to network layer information, such as at NSF NAPs or certain ATM switches, the network service provider will still have an interest in these statistics, since sorting the resulting arrays would give the NSP an indication what fraction of traffic comes from what number of users, which may be critical for planning switched or permanent virtual circuit configuration, and by the same token for accounting and capacity planning purposes. However converting virtual circuits to end customers, most likely IP customers for the near future, requires maintaining mappings to higher layers.

k claffy
Sat Apr 29 09:03:22 PDT 1995