With IPHost Network Monitor you can run simple snmp requests against a Cisco device in your network.
x21CnfGrpTable
x21 Cnf Group Table
1.3.6.1.4.1.351.110.4.5.1.1
The X21 Configuration table. The table size is given by the value of x21LineNumofValidEntries.
Back to CISCO-WAN-FR-X21-MIB MIB page.
IPHost Network monitor allows you to monitor x21CnfGrpTable 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.