2 Replies Latest reply: Nov 1, 2010 5:06 AM by Addy RSS

    About two data link questions?

    Attack at dawn

      How many twisted pairs of wires are typically used in a leased line between two routers?

      two pairs
      three pairs
      five pairs
      four pairs


      Which layer of the OSI model provides translation of data?

      data link



      Above is two quetions that I have done in the learningnetwork website,I am not sure about the two .

      First,how many twistes? I just know in lan the rj45 interface will use just 2 twisted pairs.


      Second,what does it mean "translation"? translat what?? Does it mean who receive the data and understand the data? of course,it will be application.


      Thankyou guy first, want to know how do think the quetions?

        • 1. Re: About two data link questions?

          A leased line consists of a four-wire circuit, or two pairs. One pair is for sending data, the other pair for receiving data.


          Not entirely sure, but I believe the second question is referring to the function provided by the presentation layer, which defines and negotiates data formats and deals with encryption.



          • 2. Re: About two data link questions?



            A leased line typically terminates using RJ-48C connector & uses 2 pairs of cables:

            Cables - 1&2 for Tx Tip & Ring AND 4&5 for Rx Tip & Ring.

            Presentation layer is the one that provides translation services in the OSI model. As stated by Dante, it translates data between different text formats, e.g. ASCII to EBCDIC or ANSI or Unicode etc. Remeber, presentation layer is responsible for the "syntax & semantics" of communication, both negotiation & translation.