CCNA -: WAN TOPOLOGY:-

        
                                                                -: WAN TOPOLOGY:- 

 ISDN :- Integrate Service Digital Network.
         1. This line use Copper Line Data Communication.
         2. ISDN is an example Circuit Switching Network.
         3. ISDN use two types of Channel B&D Channel.
             - The Channel B is use for Voice, Video & Data.
             - The Channel D is use for Data controlling. 
         B Channel Will be 64KBPS and D Channel will be  16KBPS & 64KBPS.( Depend on ISDN line.)
         Maximum speed ISDN line support 16 KBPS.
         4. ISDN Provides two types of line -
            i.  BRI (Basic Rate Interface) - Line Use for home purpose.
            ii. PRI (Primary Rate Interface) - Line use for commercial purpose.