ISDN can have more than 2-data channels per logical unit. There is something called E1 and T1 which has 30 and 24 B-channels respectivly per D-channel.
--HPS On Monday 10 March 2008, Alexander Leidinger wrote: > Quoting Julian Elischer <[EMAIL PROTECTED]> (from Sun, 09 Mar 2008 > > 09:33:36 -0700): > > Hans Petter Selasky wrote: > >> On Saturday 08 March 2008, Robert Watson wrote: > >>> On Sat, 8 Mar 2008, Hans Petter Selasky wrote: > >>> > >>> For example, do you > >>> anticipate using or even needing the routing facilities, and how might > >>> you map ISDN telephony parts into the normal network stack > >>> infrastructure of addresses, routing, interfaces, etc? > >> > >> Hi Robert, > >> > >> ISDN is very simple. In the ISDN world there is a term called TEI > >> which is the Terminal Entity Identifier. This kind of like an IP > >> address. > >> > >> Besides from the signalling there are 2 B-channels which can > >> transport data or audio. One of my goals is to achive zero copy > >> when moving data to/from an ISDN line and also in combination to > >> Voice over IP. Currently data is moved through userland (Asterisk > >> typically) which is usable in the short term, but in the long run I > >> want this extra copying removed. The idea is that I can route [IP] > >> packets (mbufs) through various filters in the kernel without the > >> need for copy. > > > > Given the speed of ISDN connections, It is not worth doing zero copy > > on ISDN unless you have more than 1000 of them, which seems unlikely. > > given a total throughput of 128000 b/s and the speed of current > > hardware, the number of packets per second is probably not high > > enough to make the difference even noticable. > > What about low-power embedded systems and a high count of small > packets (VoIP)? Where do you draw the line between powerful enough and > how do you chose this line? > > Bye, > Alexander. _______________________________________________ freebsd-hackers@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to "[EMAIL PROTECTED]"
