Re: VCCT and CA sniffer

[Brad Cumbia <cumbia@jlab.org>]

> 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"



That sounds good to me.

Brad Cumbia
Accelerator Network Administrator/Senior Controls Technologist
Thomas Jefferson National Accelerator Facility
Electrical Engineering Support Group
Instrumentation & Control Systems
Accelerator Computing Environment
12000 Jefferson Avenue
Newport News, Virginia 23606
Phone (757)269-5839
Pager (757)584-5839
Fax (757)269-7309
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Rok Sabjan wrote:
> 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
>
>
>
> Matthieu Bec wrote:
>
> > Hi Ned,
> >
> > Could we get a bit more description, maybe a draft from Cosylab what 
> > the plugin could possibly do? It sounds very interesting.
> >
> > Regards,
> > Matthieu
> >
> > Ernest L. Williams Jr. wrote:
> >
> > > On Fri, 2006-08-18 at 14:59 -0400, Matt Bickley wrote:
> > >
> > > > Ned Arnold wrote:
> > > >
> > > > > All -
> > > > >
> > > > > COSYLAB is interested in adding Channel Access support to Ethereal 
> > > > > (an open source protocol sniffer) ... for a small fee of course.  
> > > > > I'd like some feedback on whether this seems useful ... and how 
> > > > > much your institution would be willing to pitch in.
> > > > >
> > > > > It would be one way to feel a little more independent and confident 
> > > > > in one's ability to investigate site-specific communication 
> > > > > anomalies, so it has a real payback for your project.
> > > > >
> > > > > Send comments <and checks> to tech-talk.
> > > >
> > > > We already use ethereal, and it has been very helpful for us
> > > > in diagnosing network issues and in making us aware of poorly
> > > > behaving clients.  You have to wade through a lot of
> > > > extraneous traffic to find the CA-relevant, however.  If
> > > > ethereal had CA support, the tool would be easier to use by
> > > > anyone, not just network protocol experts.
> > >
> > > What we have done is to create some nice filters using ethereal to pick
> > > out the EPICS CA TCP and UDP traffic.
> > >
> > >
> > > Thanks,
> > > Ernest