Cisco Switching/Routing :: Cannot Find Port Number From MAC Address Using SNMP With 3725

I'm developing a project where I use the SNMP protocol to discover the network. By discovering the network I mean go through all the routers and switches and retrieve the IP routing table from routers and the forwarding table from switches. With the routers I have no problem. For the switches I need to know for each port the MAC addresses and the Vlans. Basically it's use SNMP to find a port number from a MAC address. To do that i followed this tutorial: [URL]
 
The problem is that I'm using a Cisco 3725 Router with IOS 12.4 (21) and a NM-16ESW module to work as a Switch and when I use the OID .1.3.6.1.2.1.17 corresponding to the BRIDGE-MIB as it follows:
 
snmpwalk -v2c -c myrouter 10.1.1.5 .1.3.6.1.2.1.17
 
it returns: 
SNMPv2-SMI::mib-2.17.1.1.0 = Hex-STRING: 00 00 00 00 00 00
SNMPv2-SMI::mib-2.17.1.2.0 = INTEGER: 0
SNMPv2-SMI::mib-2.17.1.3.0 = INTEGER: 4
 
From this I guess there's no information on the router about Vlans or anything. Other thing is that when I use community string indexing it returns a timeout. My theory is that this version doesn't support indexing but I don't know.
 
how can I get the Port Number from a MAC address from this "switch" (it's a router working as a switch) using SNMP?