[arm-allstar] suppressing telemetry to SIP clients

[Patrick Perdue]

Hi:

I realize this may be a bit out of scope, but I'm trying to find a 
solution for this.

On Windows, I've used a couple of softphones, particularly for net 
control, because I like the TX audio better than IaxRPT, which has a 
non-defeatable HPF. By the way, I agree with it's existence by default, 
but I'd love to turn it off and roll my own, but you can't do that. I've 
even looked in it's registry keys to see if something exists which isn't 
in the UI, but came up empty.

Anyway, with these two clients, I get a near constant stream of variable 
dumps, and messages when connects/disconnects happen sent as text 
directly to the SIP client. This causes odd behavior, different in both 
clients. I tried another SIP client on iOS, and over time, as this 
telemetry happened, the TX audio lagged farther and farther behind real 
time for every successive node variable dump.

Maybe this isn't a problem on clients (probably hard phones) that don't 
support text messaging over SIP, I don't know, but it sure is annoying. 
I have tried changing telemdefault in the node's stanza, but it appears 
to be unrelated to that. I get a full node variable dump about every 15 
seconds or so to any connected SIP client. Is there any way to suppress 
this behavior without modifying the source of the app.rpt module?

I would try Zoiper for Windows to see if that's any better, since it's 
natively using IAX2, but it's basically unusable with my screen reader.