NM-CEM-4TE1 Cisco 4-Port T1/E1 Circuit Emulation over IP Network Module

The NM-CEM-4TE1 is a Cisco four-port T1/E1 Circuit Emulation over IP (CEoIP) network module. It creates a virtual circuit across an IP network, similar to a leased line, and time-sensitive, bit-transparent traffic such as legacy data services, telemetry and radar data streams arrives unchanged. It fits the Cisco 2600XM series, 2691, 2811, 2821, 2851, 3660, 3700 series and 3800 series routers.

All four ports run in the same mode, T1 or E1, chosen once with the card type command and applied after a reload. The ports accept B8ZS line code on T1 and HDB3 on E1, and E1 lines cannot use 56 kbps connections. The dejitter buffer can be set up to 500 milliseconds, and the emulated circuit handles up to 250 milliseconds of network jitter. CAS signaling bits can be transported on channelized T1/E1 lines.

Router limits apply once all four cables are in use. On a 2600XM, four cables at the same time rule out data protection and payload compression, and framed mode then allows up to 60 channels. On a 3660, data protection works on up to two of the T1/E1 ports and framed mode allows 88 channels. Network modules and WAN cards have their own listing in Cisco interface cards.