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E1 module


1. I have one 3640 router with NM-1FE2CE1B module i need to connect E1 lease line . do i need csu/dsu (e1 modem) to connect if yes what should the modem type and interface.

may i connect serial port with e1 modem(g.703 with v.35 interface) directly if yes then what is the use of NM-1FE2CE1B module?

2. what is the use virtual-token-ring ? when it is used and what is the practical usage ?


Re: E1 module

for 1. - the NM1FE2CE1B is a channelized E1 card, you can connect this to a G.704 E1 line (using the right connectors), no csu dsu required. G.703 is not supported on this NM

Community Member

Re: E1 module

but this is having 15 pin connector so what cable i have to use,

should i use db15 - rj45 cable ?

Community Member

Re: E1 module

Dear Anil ,

1. Your modem usage depends on the backbone you r having.If you have a OFC backbone you need not have a csu/dsu and if you have a normal copper backbone you need to have 2 E1 G703 modems ( one at your premises and other at your nearest exchange). NM FE2CE1B module is channelised E1 ,you certainly need a G703 modem at your premises in case you have copper backbone to make it E1 compatible.

2. Token ring is a LAN protocol like ethernet ,which uses token passing as the technology in place of CSMA/CD of ethernet.Virtual-ring is a logical ring which helps the communication of one to any, any to any or any to one architechture of token ring networks.



Community Member

Re: E1 module

This module is channelized E1 support g.704 so what modem is appropriate for this scenrio? this module is having db 15 connector so what connector should i have for modem connection.


Re: E1 module


Maybe you can use RAD Modem with G.703/4 25 pin connector. But one thing that you have to confirm is choice RAD modem with Speed until E1.

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