NET 3710 WAN Data Networks

Network Protocols Protocols functions: Communication control – how to communicate (peer to peer, master/slave) Error detection/correction – how to check for and correct errors Link management – control traffic flow Session variables – login, authentication of users, half or full duplex Synchronization – transfer rates, timing Addressing – unique ID for nodes; connection oriented (circuit), or connectionless (packet) Routing – metrics on how best to route traffic Data segmenting/reassembly – frames, cells, packets, header and trailer Data formatting – Encryption and compression

Data Network Types LAN – Local Area Network WAN – Wide Area Network Within a building WAN – Wide Area Network Network connecting LANs in many different locations Focus on WANs

WAN Types Types of WANs Public – Internet Private – Private line, VPN, MPLS

XO IP Network XO Network Maps

IP Internet Protocol (IP) mainly an addressing scheme An IP address has two parts: the identifier of a particular network on the Internet and an identifier of the particular device (which can be a server or a workstation etc.) within that network. On the Internet itself - that is, between the routers that move packets from one point to another along the route - only the network part of the address is looked at. IPv4 uses a 32 bit address IPv6 uses a 128 bit address and provides for better QoS IP address hard to remember so Domain Name Service (DNS) is used to translate names to IP addresses.

Private WAN Types *Private Line (point to point) – Layer 1 Dedicated circuits between locations TDM or IP. TDM = T1/T3/OCx Pros – secure, reliable, dedicated bandwidth not shared, supports any protocol Cons – costly, many circuits to manage at hub or main location

Private WAN Types *Ethernet (WAN) Old layer 2 technology used on LANs Newer to WAN environment Implemented over SONET for protection or over DWDM backbones 10/100/1000MB speeds Interconnect LANs at Layer 2 Point to point or switched (FE aggregation to GigE) Pros – matching LAN speeds, simple, cheap (per MB), flat network Cons – flat network

Private WAN Types Multiprotocol Label Switching (MPLS) Layer 2 switching level Semi private/shared network Pros – utilizing existing backbone, scaleable, layer 2 – fast, one circuit to manage at HQ, cheaper than private line Cons – shared type network, not dedicated

Private WAN Types *Virtual Private Network (VPN) Layer 3 (IP) utilizing existing Internet Traffic is encrypted for security Hub and spoke or Meshed network Pros – utilizing existing network (internet), scaleable, layer 3, better use of bandwidth Cons – public network backbone, encryption overhead

Network Convergence Voice and data networks becoming one More efficient and economical Very attractive for branch office design Using dedicated or private circuits VOIP works well. Utilizing the Internet for VOIP is still unreliable.