With IPHost Network Monitor you can run simple snmp requests against a Cisco device in your network.
adslAtucInvSerialNumber
ADSL Atuc Inv Serial Number
1.3.6.1.2.1.10.94.1.1.2.1.1
Vendor specific string that identifies the vendor equipment.
Back to ADSL-LINE-MIB MIB page.
IPHost Network monitor allows you to monitor adslAtucInvSerialNumber on Cisco device via the SNMP protocol. Download IPHost Network Monitor (500 monitors for 30 days, 50 monitors free forever) to start monitoring Cisco routers right now.