Testing RJ48x

RJ48 is from the Universal Service Order Code (USOC) which is not used in LAN environments, normally. There are three versions of this, RJ48C, X and S.  

                                                         图 1. RJ48C

The DSP Series testers do not accommodate the 1&8 - 2&7 pairing BUT if you construct a special set of tester patch cables (one for each end) you can verify the performance of the installed link which would be Cat 3/Class C. You switch the pair routing from USOC to TIA in the test leads. If you do not do this and use standard RJ45 test leads, your will see Split Pair warning appear on the Autotest result.