Is There A Network Equivalent Of Alt-SysReq?

Random Q. Hacker asks: "Alt-SysReq has saved me from filesystem damage and runaway processes more than once. Unfortunately, several of the machines I admin are thousands of miles away in data centers, and it takes 15 minutes for data center personnel to go to our cage, hook up a monitor to the right system, and call back for interactive troubleshooting. I have played with snmpd, but it's a userspace daemon, and most of its functionality involves executing external programs and accessing files. Sometimes a system gets hung so bad (say, on root becoming unavailable, or memory becoming completely full) that the only thing still working is the kernel itself. Is there a kernel backdoor (as in a patch) that could let me have (secure, authenticated) SysReq functionality through the network?"