Problem : what does ar serial int and cr serial int stand for in a ppp connection

Problem : what does ar serial int and cr serial int stand for in a ppp connection

I was wondering what the “AR serial int” and “CR serial int” stand for in the setup directions for a ppp T1 connection. I realize that they are the IP addresses of the serial interfaces on the router at the client site and ISP site, but I am wondering what they stand for.

What do these abbreviations stand for?

Also I was wondering about the IP addresses that I was assinged. I was given a 255.255.255.252 mask. I have .248 for the WAN link IP,  .249 for the AR serial int ip, and .250 for the CR serial int ip. With this subnet mask, how is it that the .248 can be used as an IP, shouldnt it be the subnet ID? And is .251 used as the broadcast address?


Solution: what does ar serial int and cr serial int stand for in a ppp connection

nnnnnnnn.nnnnnnnn.nnnnnnnn.nnnnnnhh
IP      Mask      Notes …
192.168.254.248      255.255.255.252      Subnet Address
192.168.254.249      255.255.255.252
192.168.254.250      255.255.255.252
192.168.254.251      255.255.255.252      Broadcast Address

If you have a 252, then what you say is correct. (used 192.168.254.X as an example)

AR is usually “Access router, or edge router”
CR is usually “customer router”

Though I am not 100% on how it applies in the command AR/CR serial int.