:: Its probably in extended version of the old 2-in-one telecom :: line multiplexer. :: These old multiplexers, which are still in use in many :: places, (including :: big cities) are analog line doublers, where one of the voice :: signals is :: mixed up to a higher frequency, and on the other side (in :: the exchange :: normally) mixed down again. Using this system, it should be :: possible to mix :: multiple voice bands (each about 2.x Khz) on top of each :: other. ofcourse :: this requires agressive filtering, and will limit the :: bandwidth of the :: voice channel, and therefore the maximum throughput on modem :: connections. I remember that from the ADSL rollout... multiplexed lines aren't terribly good for Jetstream service ;-) -- Juha --------- To unsubscribe from nznog, send email to majordomo(a)list.waikato.ac.nz where the body of your message reads: unsubscribe nznog