Cisco NAM-1 and NAM-2 share the same hardware architecture and software applications, but are different in these respects:
NAM-2 has an additional accelerator card that provides extra-high packet-processing performance for full-scale gigabit monitoring.
NAM-2 has 1-GB RAM, while NAM-1 has 512-MB RAM.
NAM-2 supports two data ports for Switched Port Analyzer (SPAN) and VLAN Access Control List (VACL) traffic with Cisco NAM Software 3.1 and later, while NAM-1 supports one data port only. With the second data port, the Cisco NAM-2 can receive two SPAN sessions, two VACL-based captures, or one of each data source.
The SPAN sessions, each consisting of multiple ports, VLANs, or Cisco EtherChannel connections, can be used independently or together. This feature helps users view traffic on each side of a full-duplex trunk, or dedicate one data port to troubleshooting and the other data port to reporting.
NAM-2 has a larger buffer capacity than NAM-1. In Cisco NAM Software 3.4, the buffer capacity of NAM-2 is 300 MB and NAM-1 is 125 MB.