The Cisco CRS-1 Series 42-Port Gigabit Ethernet Interface Module provides 42 line-rate, IEEE 802.3-compliant Gigabit Ethernet interfaces. Physical interface characteristics can be selected using different modular Small Form-Factor Pluggable (SFP) optics - short, long, extra long, and copper interfaces are supported. Extensive per-port and per-VLAN counters simplify network performance monitoring and troubleshooting.