Experimental Physics and
Industrial Control System

Chris Payne <[email protected]> · Wed, 23 Aug 2006 11:34:44 -0700

Rok--

First off, I'm no ethereal expert, but have used it in attempts to diagnose
possible CA network problems. Any add-on or plug-in specific to CA packets
would seem to be a great addition. 

However, in the ISAC Controls system at TRIUMF we use non-standard ports 
for the main ISAC Control system. Beyond that we also use different ports 
from our main, non-standard ports for some of the secondary systems (yes, it
can get confusing). 

The reasons for these non-standard ports aside, I have a question about how 
the CA packets will be recognized. Will it be purely based on 
source/destination port, or some other header in the packet? If it will be 
based solely on ports, do you foresee the ability to customize the ports 
associated with the CA protocol in the proposed CA ethereal plug-in?

As a side note, do other labs use non-standard CA ports, or are we on our own
here?

Cheers
Chris
--
Chris Payne			ISAC Operations Controls System Manager
"Relax Snap, this is particle physics, not rocket science."

On Tue, Aug 22, 2006 at 05:34:39PM +0200, Rok Sabjan wrote:
> Date: Tue, 22 Aug 2006 17:34:39 +0200
> From: Rok Sabjan <[email protected]>
> User-Agent: Thunderbird 1.5.0.5 (Windows/20060719)
> To: Matthieu Bec <[email protected]>
> Cc: Ned Arnold <[email protected]>, EPICS tech-talk <[email protected]>
> Subject: Re: VCCT and CA sniffer
> In-Reply-To: <[email protected]>
> 
> Hi Ned, Matthieu et al.,
> 
> thanks for the interest. I asked our expert what would be the benefits 
> and here is his answer:
> 
> In addition to only filtering CA traffic, the plug-in for Ethereal would 
> also be able to 'dissect' the CA packet, that is, give meaning to the 
> plain hex-codes. Thus, every CA packet would have fields revealing 
> CA-specific information, such as:
> 
>  * what CA command is in a packet (CA_PROTO_SEARCH, 
> CA_PROTO_READ_NOTIFY, ...)
>  * what are the parameters of the command (channel name being sought 
> for, channel name that was resolved, the value of the field that was 
> returned, ...)
>  * ...
> 
> Then, filtering and searching operations could also be made relative to 
> those fields. Example filter:
> 
>   "find all packets that concern record ABCD"
> 
> I hope this is interesting enough. If you need additional information, 
> please let me know.
> 
> Best regards,
> Rok

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System