Experimental Physics and
Industrial Control System

"Thompson, David H." <[email protected]> · Wed, 30 Apr 2008 10:06:51 -0400

 This has been on our wish list for some time too.  Just being able to
identify which soft IOC a PV, or a PV collision, is coming from would be
very useful.

-----Original Message-----
From: [email protected]
[mailto:[email protected]] On Behalf Of Jeff Hill
Sent: Monday, April 28, 2008 7:29 PM
To: 'Allison, Stephanie'; 'EPICS Tech-Talk'
Subject: RE: Multiple IOCs on the same Host - question on dynamically
allocatedTCP Ports

Hello Stephanie,

The specific of how this gets configured would need to be worked out,
but
this does appear to be a good idea. If you would like I could add your
request as a Mantis entry against R3.15 so I have a reminder to look at
this
sometime before R3.15 gets released?

Jeff

> -----Original Message-----
> From: [email protected]
[mailto:[email protected]]
> On Behalf Of Allison, Stephanie
> Sent: Monday, April 28, 2008 11:04 AM
> To: EPICS Tech-Talk
> Subject: Multiple IOCs on the same Host - question on dynamically
allocated
> TCP Ports
> 
> Hello,
> 
> When multiple IOCs run on the same host, using the same
> EPICS_CA_SERVER_PORT, they use the same port for UDP channel
connection
> requests but have to use different ports for the CA TCP connection (of
> course).  The CA reference manual says:
> 
> "If the CA server library detects that a server is attempting to start
on
> the same port as an existing CA server then both servers will use the
same
> UDP port, and the 2nd server will be allocated an ephemeral TCP port."
> 
> Is there a way to set the allowable range of TCP ports that the IOC is
> allowed to choose from for its TCP port?  In particular, on a RHEL4
linux
> server.
> 
> The reason for this is that we wish to have some of our CA clients,
outside
> our firewall, connect directly to IOCs (both RTEMS and linux) inside
the
> firewall.  We don't want them to go through a CA proxy gateway process
and
> we don't want to have to set their EPICS_CA_ADDR_LISTs to include
different
> EPICS_CA_SERVER_PORT values.  We also don't want to open up our
firewall
to
> all TCP ports just to allow this communication but are willing to
allow a
> small range of predefined TCP ports.  And we don't want to combine our
IOCs
> into one.  Essentially, we want each soft IOC to use the same
> EPICS_CA_SERVER_PORT for UDP connection requests but a predefined port
for
> the TCP connection (ie, a new environment variable like
> EPICS_CA_SERVER_TCP_PORT which would be set differently in each of our
soft
> IOC startup files).
> 
> Any thoughts?  Thank you,
> 
> Stephanie Allison

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System