Ethernet WAN ports instead of serial?

Robbo777

I wanted to ask a question about wan ports on a router. These days it seems as if there aren't many CSU DSU's in play anymore and everything is done via the router, along with ethernet overtaking serial connections for wan connections? Is this true and what type of ethernet connections are used? Also, is there any need for the clock settings to be modified or are they only modified for serial interface connections?

Thanks again for the help.

kenrin

I don't know about other places but my data center uses XFP LC fiber between our core devices. For the WAN link we use single mode fiber (probably about 8 cards total). Everything else is Cat5E or Cat6, even to the NAS equipment and such.

Clock speed is only for the serial connections and the rate (if needed) would be provided by the Telco.