In case I'm attacked by black ice, the RAW says basically "no logout, difficult jacking out". But going back to AR? This way I'm not suffering dumpshock, and not logging off. I'm undecided, because this would hurt balance a lot.
Plus:

I would equate changing connection type to logging out for rules purposes. It's logical, because changing that would requiring affecting your connections in a very similar way. If you wanted to say there is some kind of physical hardware switch for that purpose, then I would definitely inflict dumpshock for using it, because the abrupt change in signal would be very much the same as manually jacking out.

You might be right. I haven't given much thought to how connections work yet, but your argument sounds sound.
Do you think switching between hot and cold sim is allowed?

I mean, switching back to AR would really cut off the simsense signal, but cold sim would only dampen it.

Normally, I wouldn't see it as a big deal, but if black IC are jamming your connecting open, I wouldn't allow you to change your connection type from hot to cold without dealing with the normal jackout/logout consequences. Again, it's an issue of abruptly altering the sensory signals (the same ones that the black IC are messing with). I'd be okay with going from cold to hot, because it's easier to open the floodgates than it is to close them. You're allowing more sensory signals in, then. But then you're stuck with the IC jamming the connection open at hot sim levels.

All this is just my own conclusions, of course. Based on the logic I perceive in the rules. None of this is really directly supported by existing rules, far as I can tell.

hmm, i would equate jacking out and dumping to AR in this regard.

still, i have a hard time to figure what exactly would be the effects of jacking out (besides disconnecting from the persona) as now that one have AR, your allways connected.

with the older matrix rules, a deck would be basicly dead if you jacked out, but with a comlink that may not be the case.

now that i think about it, this is how i would play it: if a black ice manage to get a attack, your only option is to jack out (effectively dropping the comlink into AR mode). you can then go to work trying to crash the ice so that you can log of the node its on.

or you could reboot/turn off the comlink after jacking out. but that would leave the persona "present" on the node(s) you had a active connection to for alteast half a min or something like that (plenty of time to do a trace of your last known location before the reboot).

Black IC makes the "Jack Out" action more difficult; and according to page 229 of the rules, Jacking Out is an action applied to a "Full-VR Session (with hot or cold sim)". Based on that, I'd say switching between hot and cold sim is possible on your own action.

On page 220, Jacking Out is described as "disconnecting you from your persona". Personally, I interpret this as disconnecting your MIND from your persona, as opposed to your COMMLINK (which is impossible, since your persona is just a reflection of your commlink's hardware and software, not counting Technomancers). Based on that interpretation, I'd say no, switching to AR would count as attempting to Jack Out in the case of fighting Black IC - you're trying to unmesh your mind, and the Black IC is trying to make that impossible.

I admit, though, that's partially driven by what I consider the "spirit of the rules" - if that WEREN'T true, then everyone who got hit by Black IC would use a free action to drop to AR, where they're effectively immune.

I would assume the Black IC jam's your connection as is.
For the duration, regardless of your condition or efforts.
This would seem to be at least indicated by the rules.

I tend to agree with you, NightHaunter.
But I've gotten to another question: If cold sim is legal and considered safe, then how come it allows black hammer to deal overflow physical damage?

Because when you plug your brain into a computer it's impossible to have everything be 100% safe? I'm sure every cold sim capable unit has a "warning, this device not gauranteed to protect against intrusion countermeasures." in tiny print somewhere on the box.

Oh, the Corporate Court would love that lawsuit.

"So there I was illegally intruding on a corporate system, when I get hit by their Intrustion Countermeasures. ME, an innocent, illegally tresspassing, bystander. I'm seeking damages done to me by a lawful defense system while I was in the process of committing a felony."

Is it possible to hack into a system and load your own IC, which then attacks anyone who connects to the system?

in theory yes, as ice is just agents loaded by the node in response to intruders...

edit:

crap, to slow