Frame Relay

roinuj2

Hey people, I have two questions about framerelay

1) framerelay is a packet switching protocol as opposed to a circuit switching protocol but my understanding was packet switching protocols operate at layer 3. Framerelay is a layer 2 protocol

Am i simply confusing packet switching in relation to the OSI model with
packet switching vs circuit switching?


2) If my ISP gives me a framerelay link from sydney to new york what IP addresses do i apply on each ends, Public IPs or Pivate IPs? does that information travel over the same network as the internet

Actually 3 questions.... this one linked directly to question 2
3) Does the ISP secure their ends of the frame relay link keeping it impossible (or at least not easy) for someone to perform man-in-th-middle attacks


Thanks

billscott92787

1) framerelay is a packet switching protocol as opposed to a circuit switching protocol but my understanding was packet switching protocols operate at layer 3. Framerelay is a layer 2 protocol


You are confusing layer 2 operations with layer 3 operations. I think you are thinking of layer 3 routing protocols. Remember "switching" normally operates at layer 2 - the data link layer and is not concerned really with layer 3 (network layer). Nor does it really require layer 3 to operate. I believe You are thinking more along the lines of (EIGRP, RIP, OSPF, ETC...) Layer 2 protocols such as ATM, Frame Relay, all operate at Layer 2 of the OSI model. An IP address establishes layer 3 -> IP connectivity. Frame relay is used to establish WAN links from one section to another. Normally what happens is when your ISP provides you a frame relay network, they perform their operations to ensure that "whatever" they do gets your data to the next location of your network. Chances are your network on the inside is going to be private addressing. Probably utilizing some type of public addressing scheme when passing over the WAN. (someone correct me if I am wrong please.)

Remember frame relay normally creates a PVC (permanent virtual circuit) in which data can continuously pass between to end points. This is why you see the creation of the dlci's when you set up frame relay in a lab, it creates the circuit between those two points.