TCP/IP Bridge

QNX Newsgroups (Archives) qdn.public.qnx4
#1

We make cablemodem equipment - the central office (headend) equipment
(CMTS) is a PC running QNX 4.24. The CMTS connects to a TCP/IP
Ethernet. Our equipment allows the remote subscriber equipment
(connected to a Cablemodem) to act as if it were connected to the LAN
at the headend.

Currently, we have to completely disrupt networking in the CMTS when
we start up our application. We have to stop the Net process, stop
Socket, and so on, then set them all back up with our application
running. This is because, without our application running, Net
exchanges packets with Socket (the TCP/IP process). However, our
application also wants to exchange TCP/IP traffic with Net, and Net
will can only converse with one TCP/IP process. So, with our
application up & running, our application is an intermediary between
Net and Socket.

Everything works fine, while our application is running. However,
because we destroy & re-build the Networking set up when we start our
application, we can’t start up our application remotely (via telnet,
say).

In QNX 4.25, can our application act in parallel with Socket, rather
than in serial? That is, can Net exchange TCP/IP packets both with our
app & with Socket?

Thanks
Paul McGlynn
Broadcom Corp.
770-232-0018

#2

Paul McGlynn <pmcglynn@broadcom.com> wrote:

We make cablemodem equipment - the central office (headend) equipment
(CMTS) is a PC running QNX 4.24. The CMTS connects to a TCP/IP
Ethernet. Our equipment allows the remote subscriber equipment
(connected to a Cablemodem) to act as if it were connected to the LAN
at the headend.

Currently, we have to completely disrupt networking in the CMTS when
we start up our application. We have to stop the Net process, stop
Socket, and so on, then set them all back up with our application
running. This is because, without our application running, Net
exchanges packets with Socket (the TCP/IP process). However, our
application also wants to exchange TCP/IP traffic with Net, and Net
will can only converse with one TCP/IP process. So, with our
application up & running, our application is an intermediary between
Net and Socket.

I am not totally sure, but is this means your “application” actually
is a RAW Packet program (like netraw) ? That is your “application”
regist itself to Net and getting ip/arp packet from Net ?

If that’s the case, try start Net with “-S”, this will allow both
your packet and Socket get incomming packet (Net will copy them).

I am not sure since when “Net” support “-S”, but at least V4.25D
support it. Try “sin ver” or just “use Net” to confirm.

-xtang

Everything works fine, while our application is running. However,
because we destroy & re-build the Networking set up when we start our
application, we can’t start up our application remotely (via telnet,
say).

In QNX 4.25, can our application act in parallel with Socket, rather
than in serial? That is, can Net exchange TCP/IP packets both with our
app & with Socket?

Thanks
Paul McGlynn
Broadcom Corp.
770-232-0018