With IPHost Network Monitor you can run simple snmp requests against a Cisco device in your network.
alTelnetStatsSessionSrcPort
ALTIGA Telnet Statistics Session Source Port
1.3.6.1.4.1.3076.2.1.2.11.2.1.4
The TCP source port number of the remote client.
Back to ALTIGA-TELNET-STATS-MIB MIB page.
IPHost Network monitor allows you to monitor alTelnetStatsSessionSrcPort on Cisco device via the SNMP protocol. Download IPHost Network Monitor (500 monitors for 30 days, 50 monitors free forever) to start monitoring Cisco switches right now.