With IPHost Network Monitor you can run simple snmp requests against a Cisco device in your network.
cfrFragSize
Cisco Frame Relay Fragment Size
1.3.6.1.4.1.9.9.49.1.6.1.1.1
cfrFragSize defines the payload size of a fragment and it excludes the FR headers and any FR fragmentation header.
Back to CISCO-FRAME-RELAY-MIB MIB page.
IPHost Network monitor allows you to monitor cfrFragSize 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.