I wrote some SNMP modules while working at Motorola
The modules let you send in raw network data and it would
translate it into an SNMP message object, along with a decent
API for accessing the data. It was extendable enough to
support any SNMP message format, including the volatile SNMP 3 standard.
(Sorry I had to rewrite the wheel, but I couldn't find an SNMP
package that let another do the network connection management-- we needed
a program that select()ed on multiple connections, some of which were
SNMP and others using other protocols).
The downside is that I didn't think of submitting the module
to CPAN, to technically it's still Motorola property and I
you probably couldn't get your hands on it unless you worked for them.
Of course, you're probably only interested in that module if
you wanted to mix SNMP with other protocols at the same time.
It sounds like some of the other CPAN modules would suit you
better. If you're still interested, let me know and I'll see
what I can get my hands on...