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WAN Links

Hello friends,

I'm confused about the WAN links in general especially the interfaces, channelized, unchannelized.

For example i have a E1 connection "2 M" from my telecom and i have Cisco 2821 router with WIC-1T, now i have the following questions:

- In general the serial interface supports only 2 M as a maximum, right?

- If i have a WIC-1T, i think i need an access unit to have a v.35 interface from the router side, is it better to install access unit with WIC-1T or to have another solution like NM-1CE1T1-PRI with RJ-45 interface and sure without any access units? i mean technical wise, since the first solution is cheaper.

- the G.703 is signaling or interface wise, and does it support channelized signalling or not.

What is the difference between chanelized and un-channelized E1s, is it the same as framed and un-framed?

- If the G.703 interface, is it better than the NM-1CE1T1-PRI and why?

Thanks in advance

Abd Alqader

Community Member

Re: WAN Links

Hi Alqader

See when u say u have E1 connection from ur isp u r talking about E1 signalling which provides you 2mbps of bandwidth .now u can terminate on router either on NM-1CE1T1-PRI

or serial inteface. if u terminating on NM-1CE1T1-PRI then u will need two G703 modems 1 at your place and other at exchange side .where the is MUX .if u have MUX at ur place provided by telecom then directly u can terminate on Router E1 port. if ur planning to have termination on Serial interface of rouer than u need to have a pair of modem i.e ( G703 and V.35 )V.35 at ur place and G703 at telecom. it depends on what inteface u have on router .well NM-1CE1T1-PRI card is expensive than WIC1T .Channelised E1 is segmenting E1 into logical channel .yaa u can it is same as framed and unframed.

hope so u got it .if not let me know



Re: WAN Links


Thanks for your response.

What do you mean by G703 modems? and what do you mean by MUX? is the G.703 signaling technology or it is just an interface?

The TDM & PRI are channelized since the IOS will create channel groups for them, but for the F.R it is splitted at the telecom side "F.R switch", right?

Also, i see 120-ohm and 75-ohm is this per region or what?

Thanks in advance

Abd Alqader

Community Member

Re: WAN Links

Dear brother, E1 means 2Mbps, it is using for the serial WAN Interfaces to connect the remote branches. Now understand the connectivity, how you will connect e1 link to your router. if you can't terminate directly e1 link to your router and no similar serial interface available then you will use 3rd party G.703 standard modems devices which will be intergrated with CISCO router. In this case, E1 cable terminates to G.703 interfaces and G.703 will connect to router. Data rate to 2.048 Mbps (unframed mode) or 1.984 Mbps (framed mode) per port

? Impedance: 120 ohms (RJ-45 to BNC adapter cable offers 75-ohm configuration option)

? Unframed E1, CRC4, or non-CRC4 framing. Line Impedance: 120 ohms (balanced) or 75 ohms,balanced or unbalanced. if your require more info, pls let me know?

Community Member

Re: WAN Links

In addition to my previous msg, pls review this router guide to understand the entire interface concepts . Page no. 122

Another feature link is

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