Editing X.25 (section)

==Billing==
In public networks, X.25 was typically billed as a flat monthly service fee depending on link speed, and then a price-per-segment on top of this.<ref>[http://www.itu.int/rec/T-REC-D.11-199103-I/en/ ITU-T Recommendation D.11 (03/91)], p. 2.</ref> Link speeds varied, typically from 2400 bit/s up to 2&nbsp;Mbit/s, although speeds above 64&nbsp;kbit/s were uncommon in the public networks. A segment was 64 bytes of data (rounded up, with no carry-over between packets),<ref>[http://www.itu.int/rec/T-REC-D.12-198811-I/en/ ITU-T Recommendation D.12 (11/88)], p. 1.</ref> charged to the caller<ref>[http://www.itu.int/rec/T-REC-X.7-200404-I/en/ ITU-T Recommendation X.7 (04/2004)], p. 42.</ref> (or callee in the case of reverse charged calls, where supported).<ref>[http://www.itu.int/rec/T-REC-D.11-199103-I/en/ ITU-T Recommendation D.11 (03/91)], p. 3.</ref> Calls invoking the ''Fast Select'' facility (allowing 128 bytes of data in call request, call confirmation and call clearing phases)<ref>[http://www.itu.int/rec/T-REC-X.7-200404-I/en/ ITU-T Recommendation X.7 (04/2004)], p. 38.</ref> would generally attract an extra charge, as might use of some of the other X.25 facilities. PVCs would have a monthly rental charge and a lower price-per-segment than VCs, making them cheaper only where large volumes of data are passed.