How many T1's in a DS3? How many DS3's are in an OC48? There are so many different Telecommunications Terms and Acronyms, it's no wonder that even the experts can sometimes get mixed up. There are lots of articles and definitions available on the internet, but thought we would put together our own even it's just to help me understand the difference between an OC3 and a DS3!

The basic building blocks of Telco Circuits: DS0 - 64 kb circuit - a single voice line or POTS circuit (plain old telephone service).  

24 DS0's = T1 1.544mb Circuit - 4-Wire Copper
28 T1's = DS3 45mb Circuit - Copper Coax circuit
3 DS3 = OC3 155mb Circuit - Fiber Optic Circuit

From there we move up to the OC's (Optical Carrier) These are usually considered backbone carrier circuits that connect large routers and provide service to ISP's (Internet Service Providers) or WISP's (Wireless Internet Service Providers). OC3 - 3 DS3's or 84 T1's or OC12 - 12 DS3's OC48 - 48 DS3's OC192 - 192 DS3's usually done by DWDM (dense wave division multiplexing) An OC192 would equal 5376 T1's or 129,024 voice calls!