hta@isolde.er.sintef.no (Harald Tveit Alvestrand) (04/05/91)
Someone who has done work on this stuff should be able to know.
In for example Sunlink X.25, the X.25 module is done in layers.
In the configuration file, one typical command is
iflayer $X25line $HDLCline $port
Does anyone want to guesstimate the possibility of changing this to
(lets say)
iflayer $X25line $HDLCstartstopline $ttyline
and writing an inbetween "HDLC start/stop stream module"?
Would we then have an async-X25 connection for SUN with compatibility with
other software, or are other magic tricks required?
Would this be a man-month or a man-year project?
Inquiring minds want to know (and to have cheap X.25 this year.....)
--
Harald Tveit Alvestrand
Harald.Alvestrand@elab-runit.sintef.no
C=no;PRMD=uninett;O=sintef;OU=elab-runit;S=alvestrand;G=harald
+47 7 59 70 94eckert@immd4.informatik.uni-erlangen.de (Toerless Eckert) (04/30/91)
From article <1991Apr5.073800.6984@ugle.unit.no>, by hta@isolde.er.sintef.no (Harald Tveit Alvestrand): > Someone who has done work on this stuff should be able to know. > In for example Sunlink X.25, the X.25 module is done in layers. > In the configuration file, one typical command is > > iflayer $X25line $HDLCline $port > > Does anyone want to guesstimate the possibility of changing this to > (lets say) > > iflayer $X25line $HDLCstartstopline $ttyline > > and writing an inbetween "HDLC start/stop stream module"? > Would we then have an async-X25 connection for SUN with compatibility with > other software, or are other magic tricks required? > Would this be a man-month or a man-year project? > Inquiring minds want to know (and to have cheap X.25 this year.....) The layering done in sunlink products is not a streams module layering as in SysV. It is really a stacking of ifnet structures, which originate from berkeley unix. Sun extended those structures to provide for upper and lower connecting ifnet structures. This is explained a little bit in the X.25 manual from sun. The problem is, that not every bit of the software interfaces between the layers is explained in the current documentation. Also i fear that the interface between the X.25 layer and the data link layer will change in 7.0 given that sunlink X.25 can use X.25/LLC in that version. Anyway, you might want to take a look into inria.inria.fr:/pub/x25_tcp.tar.Z from Francis Dupont (dupont@inria.inria.fr). This is a probgram which emulates the X.25 over TCP encapsulation for remote X.25 switching from cisco. It uses a pseudo LAPB level ifnet and a device triver to tunnel out the X.25 packets from the kernel and put them into a TCP socket at the user level. (That software is experimental). --- Toerless.Eckert@informatik.uni-erlangen.de /C=de/A=dbp/P=uni-erlangen/OU=informatik/S=Eckert/G=Toerless bandwidth - the final frontier.