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VWIC2-1MFT-G703 vs T1/E1 card question

blackladyJR
Level 1
Level 1

Hello,

This question seems to come up many times and getting conflicting answers.  if a CE router needs to talk to a PE router to reach MPLS network on E1 Port.  The local loop is delivered as G.703 unframed.  However PE will not configure as unframed.  PE will configure as timeslot 1-31 for a framed E1 1984k even though the loop is G.703 unframed 2048k.

Question is, does the CE must use the more expensive G703 version of VWIC2 or can CE use the cheaper VWIC2-1MFT-T1/E1 instead?

My assumption is that even though the loop is unframed, however, CE and PE are not talking unframed.  So I believe I can use the cheaper T1/E1 card on the CE and configure the card type as E1 and then configure "timeslot 1-31" under the controller even the loop is unframed G.703 2048k.  The goal is to have the CE can talk to PE and since PE will not do unframed, then, no reason to do unframed on CE side which may not even work since PE is configure as timeslot anyway.

So the real doubt is just that does CE and PE need to "match" the loop "unframed" at all?  Can CE and PE just ignore the loop being unframed and configure CE and PE as timeslot over this unframed loop?

I know I can use the G.703 card and then configure it as timeslot and it will work 100%.  However, g.703 version is more expensive compared to T1/E1 version so the cheaper card will work anyway, then why would I buy the more expensive one.

thanks.

1 Accepted Solution

Accepted Solutions

As mentioned above.

If the circuit is framed, two regular E1 cards will work.

If is is unframed, ditto.

Both ends of a circuit "create" framing, each one in it's transmit direction.

What you've been told is wrong and is a classic mistake of people unfamiliar with E1. They haven't even read the standards that says ALL E1s are G.703. And T1 also, and E3 and T3 BTW.

Please remember to rate useful posts clicking on the stars below.

View solution in original post

5 Replies 5

paolo bevilacqua
Hall of Fame
Hall of Fame

Framed E1 works on unframed circuits. That is the purpose what they are made for.

There is no need to buy the more expensive version.

thank you.  Does the PTT (Asia) when they deliver the G.703 unframed, do they need to support G.704 framing in their G.703 in order for us to use the cheaper card in CE?  This is where I am confused with.  I know in the CE when we do the timeslot option, we are pretty much configuring it as a G.703/G.704 Framed E1 1984kbps so we create the timeslot and the framing and steal the 64k for signaling use when compared to an unframed 2048k.

So does the loop provided by PTT needs to support G.704 framing in their G.703 ckt when they deliver to connect to the cheaper card?  I thought the framing is created by the CE card and the PE so I am assuming the PTT loop does not need to 'speak" G.704.  I was told the cheaper card will only work if the PTT supports G.704 which most European PTT does.  However if an PTT such as in Asia that do not support G.704, then the cheaper card won't work.  I am not sure if this is correct statement and wonder if you have any experience with it.

thanks for your confirmation.

As mentioned above.

If the circuit is framed, two regular E1 cards will work.

If is is unframed, ditto.

Both ends of a circuit "create" framing, each one in it's transmit direction.

What you've been told is wrong and is a classic mistake of people unfamiliar with E1. They haven't even read the standards that says ALL E1s are G.703. And T1 also, and E3 and T3 BTW.

Please remember to rate useful posts clicking on the stars below.

blackladyJR
Level 1
Level 1

Thank you again. I am certainly one of those that have not read the standards as well.

Other people who told me (also CCIE) telling me PTT needs to support G.704 framing in order to use cheaper card.  If I understand your message correctly where you said "If is is unframed, ditto.".  I think you mean, "even if the circuit is unframed, we can still use two regular cheaper cards and create framing by the cards on each end (i.e CE and PE) and it does not care the circuit itself being unframed and this will work", correct?  So the PTT do "not" need to support G.704 at all, correct?

So the only time we ever really need to buy the more expensive card will be a situation where we have two locations and they have a private line point to point between the two locations and they want to talk 2048k.  So in that situation, we will buy the G703 card on each end and configure "unframed" option under the controller.

So if one side is always "timeslot" (in my case my PE always and ONLY do timeslot), then my CE side will always needs to be timeslots as well, correct?  So in this situation, I never need to buy the G703 card regardless the circuit unframed or not, correct?

I am sorry to sort of asking the same question in 5 different ways as I was told by more than 2 engineers that some countries if they don't support G.704, then my cheaper card won't work.  So to be safe, always buy the more expensive card so no need to worry about it.  I do agree it's nice to just buy the more expensive card and not needed to worry at all.  However, if there is really no chance that the cheaper card won't work, then why waste the extra money if there is no chance to fail (esp, we are not referring to buy a few cards, we are referring to many many sites that not just to one customer of mine, but to many customers so hundreds of sites worldwide).  So the delta adds up very quick.

thanks again.

Your understanding is correct.

These "engineers" don't know what they are talking about. Or, they may want to sell the more expensive cards.

Thanks for the nice rating, and good luck!

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