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New Member

Channelized vs clear channel E1

Hi,

I have a few question regarding this subject. I understand a pure G.703 means clear channel = 2048kbps = unstructured E1 = unchannelized E1.

And a G.703/G.704 means a channelized E1 = 1984kbps = for data it can use timeslow 1-31 for data and TS0 is reserved for framing for G.704.

If the above two description are correct, then I assume there is no such thing "Channelized clear channel 1984k", is that correct? Someone told me about this term and I can't make sense out of this of what that means as I thought "channelized" and "clear channel" are mutually exclusive in an E1 data ckt perspective. Please correct me if this is wrong.

Now question onto the router:

If PTT delivers a 1984k E1, I will assume this mean I can use VWIC-1MFT-E1 module to connect to this handoff. And then I can configure:

Controller E1 0/0/0

channel-group 0 timeslots 1-31

So now I have a data ckt with 1984k bandwidth talking to the other side with similar config.

Question is what about if PTT deliver a clear channel 2048k ckt to me but I have no reason or need to use 2048k. I just need 1984k as I am connecting my router (CE) to a provider PE for MPLS VPN for a 1984k E1 Port speed.

So if somehow the PTT loop is 2048k to me and to provider (PTT is not same provider as MPLS provider). And if I really need 1984k instead,

a) first of all, can my VWIC-1MFT-E1 card still work on this clear channel handoff even though I really only need 1984k with timeslot 1-31?

b) if (a) is negative, so does that mean even if I just need 1984k, I still need to use VWIC-1MFT-G703 interface card?

c) If (b) is correct, then should I still configure

Controller E1 0/0/0

channel-group 0 timeslots 1-31

or should I need to configure

Controller E1 0/0/0

channel-group 0 timeslots unframed

I mean I don't want clear channel as Provider is doing 1984k for MPLS Port. So my question really is can we still do the timeslot 1-31 on an clear channel loop?

thanks,

Joyce

1 ACCEPTED SOLUTION

Accepted Solutions
Hall of Fame Super Gold

Re: Channelized vs clear channel E1

You've got an answer from an inexperienced representative, that doesn't fully understand how E1 works. This is typical especially in the USA TAC.

What you've been told here is correct and routinely done all over the word, go ahead and try.

11 REPLIES
Hall of Fame Super Silver

Re: Channelized vs clear channel E1

Hello Joyce,

as far as I know your understanding is correct.

clear channel should be

Controller E1 0/0/0

channel-group 0 timeslots unframed

the 1984 kbps framed E1 is:

Controller E1 0/0/0

channel-group 0 timeslots 1-31

all of you, PTT and MPLS provider have to agree on the service to be used: if PTT can only give unframed both DTE routers have to set unframed if then someone wants to limit speed to 1984 over it with CAR or class based policing that is a different matter.

Hope to help

Giuseppe

New Member

Re: Channelized vs clear channel E1

Hi Giuseppe,

So does that mean if PTT deliver an clear channel loop, CE and PE "must" configure with "unframed" as the only choice? Or can both CE and PE just configure "timeslot 1-31" on both CE and PE with the PTT loop being unframed 2048k anyway?

I understand what you mean by doing policing to rate limit 2048k down to 1984k throughput, but that is different than having a framed E1 that is 1984k the way it is versus an unframed E1 to shape it down to 1984k.

I am trying to understand if my loop is unframed E1 2048k by PTT, what is my configuration option in CE and PE if I just need 1984k. Will it still support timeslot 1-31 command over unframed E1 loop? Will it work?

thanks,

Joyce

Hall of Fame Super Gold

Re: Channelized vs clear channel E1

Or can both CE and PE just configure "timeslot 1-31" on both CE and PE with the PTT loop being unframed 2048k anyway?

Yes, correct.

I am trying to understand if my loop is unframed E1 2048k by PTT, what is my configuration option in CE and PE if I just need 1984k. Will it still support timeslot 1-31 command over unframed E1 loop? Will it work?

Yes. You can transport anything over unstructured E1, even non-standard framing (rate, but it exists).

New Member

Re: Channelized vs clear channel E1

Hello,

One more follow up question. So since I can just configure timeslot 1-31 over unframed E1 on both CE and PE. PE= MPLS Carrier router. Will my CE need the VWIC-1MFT-G703 card and then configure as timeslot 1-31 OR can my CE just use the cheaper card VWIC-1MFT-E1 and configure with timeslot 1-31 when the loop is unframed? In other words, can the cheaper card work when loop is unframed and we configure timeslot on it.

thanks,

Hall of Fame Super Gold

Re: Channelized vs clear channel E1

Yes, the cheaper card works just fine and that is the main rationale for using it.

However, cisco also make two more types of data-only E1 cards that may be cheaper and would support unframed for the full 2 mbps bandwidth: the HWIC-1CE1T1-PRI and the HWIC-4T1/E1.

New Member

Re: Channelized vs clear channel E1

Thank you very much for your help. I will go ahead and tried this.

New Member

Re: Channelized vs clear channel E1

hm..i opened a cisco tac case and asked the same question to Cisco and their reply is "no". They said my CE and PE should configure "unframed" only, not timeslot 1-31.

They said they don't have any documentation about this.

Hall of Fame Super Gold

Re: Channelized vs clear channel E1

You've got an answer from an inexperienced representative, that doesn't fully understand how E1 works. This is typical especially in the USA TAC.

What you've been told here is correct and routinely done all over the word, go ahead and try.

Silver

Re: Channelized vs clear channel E1

I think you have got answer to your question just to add few more lines.

E1 is always unframed at the carrier side. If carrier gives you a subrate E1/framed E1 or an different kind interface like V.35 etc, then carrier is using an extra device (called modem/converter)which you call PE, controls the speed if it is less than E1 not the SDH box which gives you an E1 (2048kbps)between locations.

New Member

Channelized vs clear channel E1

If I use clear channel, Will I lose the administration of the frame ? i.e: The alarms

Why Channalized is 1984kbps and Clear Channel is 2048 kbps? I understand that both of them use 30 channel...

Should I use UNFRAMED if i don´t use individual channel on the link ?

Thanks 

Hall of Fame Super Gold

Channelized vs clear channel E1

panchucker wrote:

If I use clear channel, Will I lose the administration of the frame ? i.e: The alarms

Why Channalized is 1984kbps and Clear Channel is 2048 kbps? I understand that both of them use 30 channel...

Should I use UNFRAMED if i don´t use individual channel on the link ?

Thanks 

Please post new instead of resurrecting old, resolved threads.

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