[1] What is SMUX?
SMUX is the snmp multiplexing protocol (RFC 1227). It can be
used by an snmp agent to query variables maintained by another
user-level process (e.g. GateD).

[2] Why is it relevant to ucd-snmp?
The ucd-snmp agent needed a mechanism to query statistics from
GateD.  GateD has traditionally supported this functionality via
SMUX.  Hence SMUX was implemented within the ucd-snmp framework
to extract routing protocol statistics from GateD.  The agent
can also communicate with other applications via SMUX.

[3] What is GateD?
GateD is the 'Gateway Daemon' which implements a variety of routing
protocols on a variety of platforms (OSes).  There is a public
version that is available free of charge.  For more information
see http://www.gated.org.

[4] What routing protocol MIBs does ucd-snmp SMUX support?
GateD supports up-to-date MIBS for all of the routing
protocols that it implements (RIP, BGP4, OSPF, etc.).  The
agent will pass down queries it receives for any other MIB
registered by a SMUX peer.

[5] Can SMUX extract statistics from other user-level processes?
Yes, the current implementation allows for the registration of
any MIB that might be registered by a SMUX peer.

[6] How does it work?
Assuming 'snmpd' is already up and running, when the SMUX
peer (e.g. GateD) comes up, it identifies itself with an
oid identifier and string password, and registers any MIBs
it would like to implement.  When 'snmpd' receives queries
for these MIBs, it passes these queries to the peer.

[7] Who implemented SMUX for ucd-snmp?
SMUX was implemented by Rohit Dube. He had oodles of help from
ucd-snmp-coders (Dave, Niels, Wes, Simon, Felix, Leonti) and 
gated-people (Acee, Feiyi, Larry, Sue). [If I missed somebody, sorry in 
advance and do let me know].  Later, Nick Amato re-write the entire
SMUX package so the code today is mostly his.

[8] How do I find out more about SMUX?
Read the RFC, the code and get in touch with ucd-snmp-coders@ece.ucdavis.edu