Network Architecture Johan Lukkien Computer Networks 2002/2003 Network Architecture Johan Lukkien 3-Aug-19 Johan J. Lukkien, j.j.lukkien@tue.nl TU/e Computer Science, System Architecture and Networking

Network Architecture Elements Nodes (hosts) Interconnect (wires + repeaters/hubs) Topology Software stack 3-Aug-19 Johan J. Lukkien, j.j.lukkien@tue.nl TU/e Computer Science, System Architecture and Networking

Network architecture design Generality: do not limit the scope unnecessarily avoid use-specific designs Robustness node & link failure: local impact limit effect of malfunctioning e.g. domains stability: left to itself the system converges to a defined & useful state e.g. no global reboots removing malfunctioning component is enough fault resilience detection: auto-diagnose Byzantine behavior 3-Aug-19 Johan J. Lukkien, j.j.lukkien@tue.nl TU/e Computer Science, System Architecture and Networking

Network architecture design Scalability design works for small and large networks e.g., performance, exploitation of locality extensions possible Configurability automatic (cf. stability), local configuration tweakable: optimizable for certain conditions Determinism Migration & evolution 3-Aug-19 Johan J. Lukkien, j.j.lukkien@tue.nl TU/e Computer Science, System Architecture and Networking

Architecture and distance home networks wireless networks long-distance wire-less 3-Aug-19 Johan J. Lukkien, j.j.lukkien@tue.nl TU/e Computer Science, System Architecture and Networking

Local area networks Typically, based on shared medium broadcasting at layer 1 or layer 2 Relatively small distance (few kilometers, at most) Simple topologies 10Base2 ethernet Star: 10(0)BaseT Token ring ownership (token) passed around owner puts packets on an removes them from the ring owner puts token on the ring again medium can be shared as well as point-2-point 3-Aug-19 Johan J. Lukkien, j.j.lukkien@tue.nl TU/e Computer Science, System Architecture and Networking

Local Area Networks High total bandwidth (the shared medium is fast) Limited number of nodes Low delay and error rate Broadcast facility supported i.e., part of the layer 2 service All nodes equal though some a bit more than others.... 3-Aug-19 Johan J. Lukkien, j.j.lukkien@tue.nl TU/e Computer Science, System Architecture and Networking

Standardizing LANs: IEEE 802 Working Groups and Study Groups 802.1 Higher Layer LAN Protocols Working Group Try to unify some issues for all LANs: management, addressing, bridges 802.2 Logical Link Control working Group Issues in connecting to the network layer 802.3 Ethernet Working Group 802.4 Token bus Working Group 802.5 Token ring Working Group 802.11 Wireless LAN Working Group 11a, 11b, 11e, 11g 802.15 Wireless Personal Area Network (WPAN) Working Group e.g. BlueTooth, ... 802.16 Broadband Wireless Access Working Group wireless MAN 802.17 Resilient Packet Ring Working Group 802.18 Radio Regulatory TAG 802.19 Coexistence TAG 802.20 Mobile Broadband Wireless Access (MBWA) Working Group Link Security Executive Committee Study Group    3-Aug-19 Johan J. Lukkien, j.j.lukkien@tue.nl TU/e Computer Science, System Architecture and Networking

Metropolitan Area Networks Three components the access network for end-users at the end-user you may find a LAN again... connect to long-haul access points specifically serve enterprises e.g. file storage, disparate locations Requirements diverse access technology xDSL, cable, telephony, fiber diverse managerial domains home/enterprise equipment, PTT, cable company, leased lines locally: fast, reliable and fair similar technologies as LAN, if possible 3-Aug-19 Johan J. Lukkien, j.j.lukkien@tue.nl TU/e Computer Science, System Architecture and Networking

MANs: examples Regular, special purpose networks cable TV: just broadcasting and multiplexing of signals across the same physical medium telephony: full duplex, point to point, connection oriented electricity General data communication re-use existing infrastructure 3-Aug-19 Johan J. Lukkien, j.j.lukkien@tue.nl TU/e Computer Science, System Architecture and Networking

Cable and telephony Cable Telephone need to add two-way communication sharing of cable segments Telephone low bandwidth UTP 3-Aug-19 Johan J. Lukkien, j.j.lukkien@tue.nl TU/e Computer Science, System Architecture and Networking

Wide Area Networks Long-range geographical distribution Separation of local net and subnet different management subnet: just transport – wires, switches, routers (no hosts!) Path-oriented transport through the subnet Note: subnet properties will affect WAN services 3-Aug-19 Johan J. Lukkien, j.j.lukkien@tue.nl TU/e Computer Science, System Architecture and Networking

Routing (path oriented) 3-Aug-19 Johan J. Lukkien, j.j.lukkien@tue.nl TU/e Computer Science, System Architecture and Networking

Internetworks Connecting distinct networks add a subnet: WAN connect using multi-ported devices in an existing network e.g. WAN-connected LANs No clear terminology for Internetworks but must have different technologies and different managerial domains Note: technical distinctions (WAN, LAN, MAN...) are vanishing managerial distinctions are most relevant 3-Aug-19 Johan J. Lukkien, j.j.lukkien@tue.nl TU/e Computer Science, System Architecture and Networking

Wireless Bandwidth sharing in cells Two modes Overlap issues point-to-point base-station (star) Overlap issues Three distance scales Wire-replacement LAN technology WAN technology 3-Aug-19 Johan J. Lukkien, j.j.lukkien@tue.nl TU/e Computer Science, System Architecture and Networking

Wireless (cnt’d) Wire-replacement LAN technology WAN technology relatively low bandwidth : main focus on system interconnect (BlueTooth, wireless USB); P2P cells roughly 10m LAN technology include link layer technology ‘high’ bandwidth (i.e., only a factor of 10-100 slower than wired); e.g. HiperLan, IEEE 802.11 (‘WiFi’) cells up to 100m P2P or base-stations WAN technology use long-haul connections, e.g. GSM, GPRS, UMTS cells up to 3 km base-stations 3-Aug-19 Johan J. Lukkien, j.j.lukkien@tue.nl TU/e Computer Science, System Architecture and Networking

Home networks Special requirements diverse hardware and interconnect Information, Communication, Entertainment, Control must work, reliable, foolproof low cost much streaming, rather than bursty traffic high capacity does not work well with ethernet evolutionary path equipment is there for years to stay safe, secure, privacy protection 3-Aug-19 Johan J. Lukkien, j.j.lukkien@tue.nl TU/e Computer Science, System Architecture and Networking

Connecting everything: the Internet 3-Aug-19 Johan J. Lukkien, j.j.lukkien@tue.nl TU/e Computer Science, System Architecture and Networking

Exercises Exercise 38 on page 84 3-Aug-19 Johan J. Lukkien, j.j.lukkien@tue.nl TU/e Computer Science, System Architecture and Networking