Allocation versus Usage
Nearly 17,000 ASes allocated as of November, 2000.
About 9,000 in use at that time (nearly 10,000 today).
Geoff Huston notes that the nearly 8,000 unused ASes are:
- historically allocated AS numbers that are lost in the system;
- historically allocated AS numbers that are used in a semi-private context; or
- recently allocated AS numbers yet to be deployed (most common).
Seems to imply that ASes are allocated four to six months in advance of use, which suggests that exhaustion might occur in the first half of 2005 rather than the second half.
Phillip Smith is investigating AS usage anomalies.