Input packets getting dropped

[karthikvish2000]

Cisco 2620XM with Serial 2T card and frame-relay connection is having a lot of input packet drops on S0/0. Utilisation of the interface never goes above 50% in both directions.

Monitoring tools indicate that input drops happen even when input BW utilisation is as low as 20%. What could be the possible reason behind the drops?

[Joseph W. Doherty]

Have you seen these docs?

http://www.cisco.com/en/US/products/hw/routers/ps133/products_tech_note09186a0080094791.shtml#topic2

http://www.cisco.com/en/US/products/hw/modules/ps2643/products_tech_note09186a0080094a8c.shtml#input

They're not specific for your platform, but such issues often seen on different platforms.