SDN/SDDC Retreat in Miami, Florida (November 4th-6th)
Separate SDN hype from real life!

X.25 is still kicking

The results of the X.25 poll amazed me. I thought X.25 was long dead, but around 10% of people responding to the survey indicated they are still using it (primarily to connect the legacy equipment) and more than half of the respondents had to configure it in the past (I didn't know we were all going so far back :).Obviously some very big networks are still heavy X.25 users, as Cisco has been implementing more and more X.25-related features (primarily in the XOT space) in recent years … if only they would have been available when I really needed them 15 years ago :(.

By now you should be asking yourself “Well, so what's the latest and greatest X.25 feature?” Brace yourselves: 12.4(15)T has introduced support for X.25 accounting and the Call Detail Records (CDRs) are generated as syslog messages.


  1. Old technologies never die, they are just waiting their turn to come back again.

    Consider IPXng, looks a lot like IPv6 to me.

  2. It sure does look like it. If nothing else, than at least the addresses look similar


You don't have to log in to post a comment, but please do provide your real name/URL. Anonymous comments might get deleted.

Ivan Pepelnjak, CCIE#1354 Emeritus, is an independent network architect. He has been designing and implementing large-scale data communications networks as well as teaching and writing books about advanced technologies since 1990. See his full profile, contact him or follow @ioshints on Twitter.