NET6.PPT
- 2. Network design considerations Building blocks of a LAN/WAN network Intelligent hub Bridge LAN Switch Router Telephone Company Service Options Leased Lines Switched 56 ISDN Frame Relay ATM Sequence
- 3. TCP/IP SNA IPX DECnet WAN Novell LAN Server NETBIOS IBM LAN Server IBM Mainframe UNIX Workstation Digital Host SNA IBM Controller AppleTalk Apple LAN ? ? ? ? LAN/WAN Integration
- 4. "Routable" vs. "Non-routable" TCP/IP IPX APPN Connectionless vs. connection-oriented transport TCP/IP IPX Broadcasts/route updates NetBIOS - Name Query TCP/IP - ARP, RIP, OSPF NetWare - Service Advertising Protocol (SAP), RIP Appletalk - Zone Information Protocol (ZIP) & AARP NetBIOS DECNET SNA SNA NetBIOS Protocol Implications
- 5. Broadcast Frame Netware Get Nearest Server Query Netware Server IPX Broadcast Example
- 6. Network design considerations Building blocks of a LAN/WAN network Intelligent hub Bridge LAN Switch Router Telco WAN Options Leased Lines Switched 56 ISDN Frame Relay ATM Agenda
- 8. Source Routing Bridges At layer 1, isolates LAN segments to increase performance, availability At layer 2, connects LANs into a single logical network Functions independently of higher layer protocols Operates as plug and play device B B B B B B B B B B B B Transparent Bridges Bridge
- 9. Bridge Bridge Bridge Bridge Bridge Broadcast Frame Bridge Bridge Netware Server Netware Get Nearest Server Query Broadcast Example
- 10. Token Ring Bandwidth 0 1,000,000 2,000,000 3,000,000 4,000,000 4,000,000 1,544,000 528,000 256,000 128,000 64,000 19,200 9,600 T1 512K 256K 128K 64K 19.2K 9.6K Relative Bandwidth of various media
- 11. Net A Net C Net D Net E Net 2 Isolates logical subnetworks for more efficient network utilization over WAN End station sends traffic to router; router forwards toward ultimate destination Routing protocols allow router to understand network topology DSU/CSU DSU/CSU DSU/CSU Router Router Router Net B Net 3 Net 1 Router
- 12. Router Router Router Router Router Broadcast Frame Bridge Bridge Netware Server Netware Get Nearest Server Query Broadcast Example
- 13. Router WAN Considerations Port Density Port Cost Multiprotocol Primary Role Provide Managed Bandwidth for Slower WAN Lines Switch Router Router WAN 9.6K 19.2K 64K 128K 512K 1.544 MB LAN 4MB 10MB 16MB 100MB 155MB
- 14. WAN Challenge Enterprise spans multiple locations Requirement to share information or applications between the locations Must balance performance against cost Raleigh, NC Richmond, VA
- 15. Components of a Wide-Area Network Raleigh, NC LEC e.g. BellSouth LEC e.g. Bell Atlantic IXC e.g. AT&T, Sprint, MCI,... LEC = "Local Exchange Carrier" IXC = "Inter-Exchange Carrier" "Local Loop" "Local Loop" Richmond, VA
- 16. "Leased Line" Network Raleigh, NC LEC LEC IXC LEC = "Local Exchange Carrier" IXC = "Inter-Exchange Carrier" = carrier multiplexing Richmond, VA Carrier-provided facility – "owned" bandwidth – idle facility unused Low latency – data simply relayed from one set of wires to the next High cost – especially for LAN applications
- 17. "Switched" Network Services Raleigh, NC LEC LEC IXC Analog dial Integrated Services Digital Network (ISDN) Narrowband/Wideband/Broadband Switched 56 Richmond, VA Lowers Line Cost Charged for usage time Requires Call Setup & Call Take Down
- 18. WAN Technologies Fast Packet Switching Frame Relay Cell Relay ATM SMDS – Efficient handling of variable- sized frames – data only (today) – up to 1.5Mbps (today) – Scalability (up to Gbps) – QoS – Voice/Vide o/ Data/MM Cost-effective shared facilities – with some built-in bandwidth management Low latency – connection-oriented packet forwarding – no hop-by-hop error checking ATM: Asynchronous Transfer Mode SMDS: Switched Multimegabit Data Services
- 19. Local Carrier Frame Relay Networking Raleigh, NC LEC Frame Relay Service LEC = "Local Exchange Carrier" = switch Chapel Hill, NC
- 20. Inter-Exchange Frame Relay Networking Raleigh, NC LEC LEC Frame Relay Network LEC = "Local Exchange Carrier" IXC = "Inter-Exchange Carrier" = carrier multiplexing = switch Richmond, VA
- 21. Frame Relay Network ROUTER Multiple virtual circuits over a Single Physical Link Pricing is usually lower and distance-insensitive however tariffs vary widely Can be a cost-effective alternative to private lines Bandwidth specified via Committed Information Rate & Burst Size Router Router Router Router
- 22. Cell Relay: Asynchronous Transfer Mode (ATM) Digital service starting at 45Mbps Fixed length "cells" of data Voice, video, data, multimedia Bandwidth Management ITU-T Q.2931 Quality of Service
- 23. Quality of Service: A Key Concept... – Quality of Service (QoS): – A set of parameters that specify the required characteristics of a network path – Include characteristics such as throughput, acceptable delay, tolerance for cell loss,... – Specified in the ATM User to Network Interface (UNI) standards Gives users the ability to specify what is required Gives the "network" responsibility to: – allocate and free the required network resources – guarantee that committed network characteristics are met "QoS"
- 24. Removing the WAN Bottleneck Switch Router Router LAN 4MB 10MB 16MB 100MB 155MB WAN 9.6K 19.2K 64K 128K 512K 1.544 MB
- 25. ATM Extended Campus Switch Extended LAN Environment Multiprotocol Campus Network "Business as Usual" LAN 4MB 10MB 16MB 100MB 155MB WAN 45MB 100MB 155MB Switch
- 26. WAN Technologies Fast Packet Switching Exploits new technologies to achieve better performance characteristics Some built-in bandwidth management Leased Lines Carrier-provided facility – "owned" bandwidth – idle facility unused Low latency – data simply relayed from one set of wires to the next High cost – especially for LAN applications Switched (Switched 56, ISDN) Lowers the cost of leased lines by charging for usage time Requires effort to set up and tear down call at appropriate times
- 28. Saving Costs With Frame Relay OKReset OKReset OK Reset OK Reset Frame Relay WAN
- 29. Evolution: Exploiting an ATM Backbone OK Reset OKReset OKReset Frame Relay ATM Backbone OK Reset
- 30. Evolution: Supporting Time-Sensitive Applications OK Reset OK Reset OK Reset Frame Relay ATM Backbone MM Server MM Client Multi-Service Access Switch Multi-Service Access Switch Video Conferencing Video Conferencing OK Reset
- 31. How do you choose the right technology? Data Center Infrequent use Frequent use Dedicated Access Switched Access High Bandwidth
- 32. Choosing the Right Services Switched Access - Occasional Use Dedicated Access - Frequent Use High-Bandwidth - Specialized Applications Leased Line - low delay, simple, reliable Frame Relay - potentially lower cost, cost effective support of bursty traffic Analog Dial - simple, low-bandwidth, inexpensive Switched 56 - equipment inexpensive, future??? ISDN - expensive equipment (depending on features), service pricing??? ATM - Voice, Video, Multimedia SMDS - future???