1. © 2000 B. Stiller, B. Plattner ETHZ-TIK, D. Bauer IBM Research CM III – 1 ETH Zürich Part III: Overview of Technologies, ATM, and IP Overview of Networking Technologies – Developments – High-speed Characteristics – Switching Techniques ATM (Asynchronous Transfer Mode) – Principles of Cell Switching – ATM Connection Management – ATM Layer and Adaptation Layer IP (Internet Protocol) – Key Elements – Protocol Stack

2. © 2000 B. Stiller, B. Plattner ETHZ-TIK, D. Bauer IBM Research CM III – 2 ETH Zürich Networks o Networks provide an infrastructure for: Interconnecting machines or services (connectivity), Making available scarce resources (resource sharing), Equalizing traffic volumes (load balancing), and Providing alternative fallbacks (reliability). o Structuring networks according to dimensions: Expansion (LAN, MAN, WAN), Topology (star, ring, bus, meshed), Performance (low-speed, high-speed, real-time), Administration (public, private), and Task (internet or physical net, intranet or virtual net).

3. © 2000 B. Stiller, B. Plattner ETHZ-TIK, D. Bauer IBM Research CM III – 3 ETH Zürich Inventions in Telecommunications Oscillating needle telegraph experiments Early telegraphy (Morse code dots and dashes) Printing telegraph systems Baudot multiplex telegraph (6 machines on one line) First telephone channels constructed First carrier telephony Carrier telephony carries 12 voice channels on wire 60 voice channels over coaxial cable 600 voice channels over cable (T3) and microwave 3600 voice channels over cable and microwave 32000 voice channels over cable 108000 voice channels over cable Multimode optical fiber 45 Mbit/s Multimode optical fiber 140 Mbit/s Monomode optical fiber 565 Mbit/s Monomode optical fiber 16 Gbit/s 1850 1860 1870 1880 1890 1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000 Year 1800 voice channels over cable and microwave 10 12 10 1110 10 9 10 8 10 7 10 6 10 5 10 4 10 3 10 2 10 1 Bandwidth bit/s                 

4. © 2000 B. Stiller, B. Plattner ETHZ-TIK, D. Bauer IBM Research CM III – 4 ETH Zürich Transmission Media o Fiber optical media: Low error rates, long distances, low attenuation. Attenuation [dB/km] 10 0 1 2 3 0 1 Frequency [MHz] 10 2 Copper (UTP) Copper (Coaxial) Fiber (Multimode) Fiber (Monomode) Fiber (Gradient)

5. © 2000 B. Stiller, B. Plattner ETHZ-TIK, D. Bauer IBM Research CM III – 5 ETH Zürich o Last Mile Problem: Connection between the home and the backbone is serious. Requires a huge capital investment. Fiber ignores the last mile problem. Evolution of Bandwidth Bandwidth [kbit/s] 1975 10 0 1 Time [year] 10 2 3 4 5 6 7 198019851990199520002005 POTS WAN LAN POTS WAN Local Area Network Plain Old Telephone Service Wide Area Network

6. © 2000 B. Stiller, B. Plattner ETHZ-TIK, D. Bauer IBM Research CM III – 6 ETH Zürich High Speed Networks – Overview (1) o High Speed Local Area Networks (LAN): Fast Ethernet: 100 Mbit/s Gigabit Ethernet: 1.0 Gbit/s HIPPI: 800 Mbit/s Fiber Channel: 100, 200, 400, or 800 Mbit/s High Speed Token Ring: 100 Mbit/s (1 Gbit/s) o High Speed Metropolitan Area Networks (MAN): FDDI: 100 Mbit/s FDDI-II: 100 Mbit/s (incl. isochronous channels) DQDB: 34 Mbit/s, 155 Mbit/s, or 622 Mbit/s o High Speed Wide Area Networks (WAN): ATM-based B-ISDN: e.g., 2, 34, 155, 622, or 2,400 Mbit/s

7. © 2000 B. Stiller, B. Plattner ETHZ-TIK, D. Bauer IBM Research CM III – 7 ETH Zürich High Speed Networks – Overview (2) o Carrier support (physical layer): Plesiochronous Digital Hierarchy (PDH): –e.g., DS-0: 0.064 Mbit/s (= 1 voice channel) – T-1 (USA): 1.544 Mbit/s (  24 voice channels) (also called DS-1) – E-1 (Europe): 2.048 Mbit/s – E-3 (Europe): 34.368 Mbit/s – T-3 (USA): 44.736 Mbit/s (also called DS-3) Synchronous Digital Hierarchy (SDH) or Synchronous Optical Network (SONET): –e.g., STS/OC-1: 51.84 MBit/s – STS/OC-3: 155.52 MBit/s (  STM-1) DS: Digital Signal T: Telephone Line OC: Optical Carrier STS: Synchronous Transfer Signal Level

8. © 2000 B. Stiller, B. Plattner ETHZ-TIK, D. Bauer IBM Research CM III – 8 ETH Zürich High Speed Networks – Overview (3) o Carrier support (physical layer) continued: Wavelength Division Multiplexing (WDM) o Access technologies: Cable TV Frame Relay (FR) xDSL (Digital Subscriber Line) Satellite networks and wireless local loop o Service technologies: Switched Multimegabit Data Service (SMDS)

9. © 2000 B. Stiller, B. Plattner ETHZ-TIK, D. Bauer IBM Research CM III – 9 ETH Zürich HSTR Fast Ethernet xDSL Token Ring Ethernet FDDI, DQDB, CRMA X.25 N-ISDN STM ATM LAN Network Dimensions System Bus  1980/90  1980  1990 10 Transmission rate [Mbit/s] 10 -3 10 -2 10 0 1 2 3 4 -3 10 -2 10 10 0 1 2 Distance [km] 10 3 Wide Area Network  2000  1985 Local Area Network  1995 Metropolitan Area Network  1995 HIPPI  1990 ATM-based B-ISDN

10. © 2000 B. Stiller, B. Plattner ETHZ-TIK, D. Bauer IBM Research CM III – 10 ETH Zürich Protocol Layer Architecture – Examples SDH/SONETWDM ADSL: Asymmetric Digital Subscriber Loop ATM: Asynchronous Transfer Mode HDLC: High Data Link Control IP: Internet Protocol PPP: Point-to-Point Protocol WDM: Wavelength Division Multiplexing SDH/SONETADSL Transmission Convergence VoiceHDLC Video ATMPPP IPVoiceIP... Voice telnet...

11. © 2000 B. Stiller, B. Plattner ETHZ-TIK, D. Bauer IBM Research CM III – 11 ETH Zürich Characteristics of High Speed Networks o Characteristics of high speed networks: Low bit error rate (fiber optical media), Higher packet error rate (buffer overflow), Existing Jitter (different buffer lengths), Small transmission units (cells), Many connections (context data), High bandwidth (fiber optical media), and Extreme bandwidth-delay product. o Protocols have to deal with these issues to alleviate influences of delayed, corrupted, or lost data.

12. © 2000 B. Stiller, B. Plattner ETHZ-TIK, D. Bauer IBM Research CM III – 12 ETH Zürich File Transfer Example File size: 1 Mbyte Link: San Diego – Boston Signal delay: 25 ms o 64 kbit/s channel: 64 kbit/s * 25 ms = 1,600 bit 0.02 % of file on link o 2 Mbit/s channel: 2 Mbit/s * 25 ms = 50,000 bit 0.6 % of file on link o 1 Gbit/s channel: 1 Gbit/s * 25 ms = 25,000,000 bit 8 ms for transmission, 17 ms idle SANBOS SAN BOS 1,600 bit 50,000 bit 25,000,000 bit 5000 km Bits are smaller – not faster !

13. © 2000 B. Stiller, B. Plattner ETHZ-TIK, D. Bauer IBM Research CM III – 13 ETH Zürich Effects on Data in Transit o Signal delay is dominating the transmission delay. This grows worse for high transmission rates. o Buffer overflows dominate occurring errors. The effect grows worse for fast and real-time traffic. o Error recovery has to be a trade-off between a waste of bandwidth or extending delays. Bandwidth is much cheaper than tolerating high delays. Multimedia applications normally don´t like delays. o A huge amount of data is in transit within high speed and long distance networks  Path Capacity P C : P C = B * D signal B: Bandwidth, D signal : Signal delay.

14. © 2000 B. Stiller, B. Plattner ETHZ-TIK, D. Bauer IBM Research CM III – 14 ETH Zürich Switching Techniques – Overview o Switching Techniques: Based on circuits, cells, frames, or packets. o Circuit switching suffers from fixed bandwidth constraints for bursty traffic. o Packet switching allows for variable bandwidth. Circuit Switching (STM) Fast Circuit Switching ATM Frame Relay Packet Switching Fixed Behavior of Bandwidth Variable Multirate Circuit Switching Fast Packet Switching Frame Switching Intricacy SimpleComplex

15. © 2000 B. Stiller, B. Plattner ETHZ-TIK, D. Bauer IBM Research CM III – 15 ETH Zürich o Circuit information are stored during establishment times in a translation table. Delay is determined by the propagation delay and the processing in switches. Bounded to 450  s by ITU-T. Bit error rates are caused by single bit errors (switch- ing malfunction) or bursts (loss of synchronization). o Inflexible, e.g., G.703 PCM. Fixed bandwidth. Circuit Switching l1l2lml1l2lm Incoming Link Time Slot Outgoing Link Time Slot 12…m12…m 12…m12…m 12…m12…m O1O2O3…O1O2O3…O1O2O3…O1O2O3…O1O2O3…O1O2O3… 32…132…1 42…m42…m 1m…11m…1

16. © 2000 B. Stiller, B. Plattner ETHZ-TIK, D. Bauer IBM Research CM III – 16 ETH Zürich Packet Switching o Based on user data that are encapsulated in packets. o Concept is based on technology available in the 60s: Erroneous links: –Link-based error control in complex protocols. Low bandwidth links: –High delays (due to retransmissions) and low speed (due to protocol processing) –Lacking support of real-time and multimedia traffic Software-based protocol implementations: –Variable sized packets require a complex buffering. o X.25 is the oldest example of packet switching nets.

17. © 2000 B. Stiller, B. Plattner ETHZ-TIK, D. Bauer IBM Research CM III – 17 ETH Zürich Frame Relay (1) o Frame Relay supports connection-oriented services. o Subscriber Network Interface (SNI) defined between customer (router) and PTO equipment. Support of pure data, not particularly voice etc. Multiplexes flows of data being divided in data blocks. Flows are carried in virtual channels which may exceed their bandwidth as other channels are idle. Frame Relay may carry X.25 packets/frames. o Performance: Different implementation approaches exist, however, 2 Mbit/s access speeds are common. Insufficient guarantees on bandwidth and delay variation. PTO: Public Telecommunication Operator

18. © 2000 B. Stiller, B. Plattner ETHZ-TIK, D. Bauer IBM Research CM III – 18 ETH Zürich Frame Relay (2) o Physical and data link layer specifications available. o The data link layer is based on LAPD (ISDN): Data link services: addressing (DLCI, local significance). Error control is left out as an end-to-end function. Core LAPD frame: DLCI: Data Link Connection Identifier C/R: not used EA: Extended Address FECN: Forward Error Congestion Notification BECN: Backward Error Congestion Notification DE: Discard Eligibility FlagAddressPayloadFCSFlag 12variable21 Byte DLCIC/READLCIFECNBECNDEEA 6bit1141111 01111110

19. © 2000 B. Stiller, B. Plattner ETHZ-TIK, D. Bauer IBM Research CM III – 19 ETH Zürich Frame Relay (3) o Frame Relay DLCI assignments: o A simple sample Frame Relay network: User B User C User A Permanent Virtual Circuits 16 1007 145 1007 16, 145, 1007: DLCI 0Reserved for Call Control Signaling 1-15Reserved 16-1007Assigned to Permanent Virtual Circuits (PVC) 1008-1022Reserved 1023Local Management Interface Frame Relay Interface

20. © 2000 B. Stiller, B. Plattner ETHZ-TIK, D. Bauer IBM Research CM III – 20 ETH Zürich Comparison o Summary of important functional differences: Connection-oriented Connectionless Frame Boundaries Bit Stuffing CRC Error-Control ARQ Flow-Control Multiplexing of log. Channels X.25  –  Frame Switching  or   – Frame Relay  –  – Light weightHeavy weight Technology CRC: Cyclic Redundancy Check

21. © 2000 B. Stiller, B. Plattner ETHZ-TIK, D. Bauer IBM Research CM III – 21 ETH Zürich Part II: Overview of Technologies, ATM, and IP Overview of Networking Technologies – Developments – High-speed Characteristics – Switching Techniques ATM (Asynchronous Transfer Mode) – Principles of Cell Switching – ATM Connection Management – ATM Layer and Adaptation Layer IP (Internet Protocol) – Key Elements – Protocol Stack

22. © 2000 B. Stiller, B. Plattner ETHZ-TIK, D. Bauer IBM Research CM III – 22 ETH Zürich Cell-based Switching o Integration of a variety of services: Bursts are smoothened. Isochronous data are delivered according to their jitter. Data may be multiplexed statistically, if the overall bandwidth is sufficient. o Efficiency: statistical multiplexing gain. o Delay problems occur in case of sending packets of different length. Extremely long blocking can be avoided, if cells of fixed-size are used. If the overall cell length is too big, a similar problem appears.

23. © 2000 B. Stiller, B. Plattner ETHZ-TIK, D. Bauer IBM Research CM III – 23 ETH Zürich Handling Cells – Segmentation/Reassembly o To sent packets over cell-based networks, packets have to be segmented and reassembled again. o The segmentation and reassembly (SAR) functionality is placed right above the cell level. Packet Cells HLP User Data SARHLP UD User Data Cell UD SARHLP CellSAR User Data Cell SAR User Data SAR User Data SAR Cell Header SAR Header... HLP Higher Layer Protocol Header Total Cell Length Cell Payload Length

24. © 2000 B. Stiller, B. Plattner ETHZ-TIK, D. Bauer IBM Research CM III – 24 ETH Zürich Structure of an ATM-based B-ISDN Network Customer Premises Equipment ATM- Switch NNI UNI ATM-connected MM-Workstation ATM-connected MM-Workstation ATM: Asynchronous Transfer Mode MM:Multimedia NNI: Network Node Interface UNI: User Network Interface ATM- Switch ATM- Switch ATM- Switch NNI ATM- Switch Core ATM-Switch Edge ATM-Switch ATM- Switch

25. © 2000 B. Stiller, B. Plattner ETHZ-TIK, D. Bauer IBM Research CM III – 25 ETH Zürich B-ISDN Reference Model – I.321 o Modeling communication systems is done in a logically hierarchical structure, e.g., ISO/OSI BRM. o Relation between OSI and B-ISDN/ATM undefined. o The plane approach has been used within B-ISDN. Physical Layer ATM Layer ATM Adaptation Layer Higher Layer Protocols Management Plane Control P.User P. Plane Management Layer Management P.: Plane

26. © 2000 B. Stiller, B. Plattner ETHZ-TIK, D. Bauer IBM Research CM III – 26 ETH Zürich ATM Connections (1) o Connections, links, ATM equipment, and identifiers: ATM End-system ATM End-system ATM Cross-connect ATM Switch ATM Cross-connect ATM Switch VCC 1 VPC 1 VPC 2 VPC 3 VCI 1 VCI 2 VCI 3 VPI 1VPI 3VPI 5VPI 2VPI 4 VPL 1VPL 3VPL 5VPL 2VPL 4 VC: Virtual Channel, VP: Virtual Path, L: Link, I: Identifier, C: Connection Links Equipment Identifiers “Connections”

27. © 2000 B. Stiller, B. Plattner ETHZ-TIK, D. Bauer IBM Research CM III – 27 ETH Zürich ATM Connections (2) o Hierarchical connection concept includes: Virtual Connections are identified by two identifiers, which are significant only locally per link in the virtual connection. –Error-control is done end-to-end only, if required. q High quality links and a good call acceptance control. –Flow-control is not provided. q High bandwidth delay product. Virtual Channel (VC) is a uni-directional channel, identified by the Virtual Channel Identifier (VCI). –Dynamically allocatable connections. Virtual Path (VP) contains a group of VCs, identified by the Virtual Path Identifier (VPI). –Statically allocatable connections.

28. © 2000 B. Stiller, B. Plattner ETHZ-TIK, D. Bauer IBM Research CM III – 28 ETH Zürich ATM Connections (3) o Simultaneous support of many thousands of VCs requires the ATM cell to carry the VCI field. o Supporting many semi-permanent connections between endpoints, carrying many grouped VPs requires the ATM cell to carry the VPI field. Link VPI 1 VPI k VCI n VCI m VCI 1 VCI 2 VPIVirtual Path Identifier VCIVirtual Channel Identifier Pre-assigned VPI/VCI values: 0/0Unassigned, idle 0/1Meta-signaling 0/3Segment flow (between VP end-points, F4) 0/4End-to-end F4 flow 0/5Signaling 0/15SMDS 0/16ILMI ILMI: Integrated Layer Management Interface SMDS: Switched Multimegabit Data Service

29. © 2000 B. Stiller, B. Plattner ETHZ-TIK, D. Bauer IBM Research CM III – 29 ETH Zürich ATM Switching (1) o Two types of switching may be performed. o VP switching (ATM Cross-connect): Switching between VPs, No evaluation and change of VCIs, Change of VPIs, and Variable number of VCs per VP possible. o VC/VP switching (ATM Switch): Switching in close cooperation between VCs and VPs, Evaluation of VCI and VPI in an intermediate system, Change of VCI and VPI if necessary, and Incoming VCs of one VP may be distributed between many outgoing VPs.

30. © 2000 B. Stiller, B. Plattner ETHZ-TIK, D. Bauer IBM Research CM III – 30 ETH Zürich ATM Switching (2) o Use of VPI in a B-ISDN network (cross-connect). ATM PHY B-ISDN Network ATM PHY ATM PHY VPI in VPI out 75 97 VPI = 7 VCI = 1, 2, 3 VPI = 3 VCI = 3, 4 VPI = 9 VCI = 3, 4 VPI = 7 VCI = 1, 2, 3 VPI = 5 VCI = 1, 2, 3 VPI = 7 VCI = 3, 4 VPI in VPI out 57 VPI in VPI out 73 A B C 1 2 3

31. © 2000 B. Stiller, B. Plattner ETHZ-TIK, D. Bauer IBM Research CM III – 31 ETH Zürich ATM Switching (3) o Use of VPI-VCI in a B-ISDN network (ATM switch). ATM PHY B-ISDN Network ATM PHY ATM PHY VPI-VCI in VPI-VCI out 7.15.1 7.27.3 7.35.2 9.37.4 9.45.3 VPI = 7 VCI = 1, 2, 3 VPI = 3 VCI = 3, 4 VPI = 9 VCI = 3, 4 VPI = 7 VCI = 1, 2, 3 VPI = 5 VCI = 1, 2, 3 VPI = 7 VCI = 3, 4 VPI-VCI in VPI-VCI out 5.17.2 5.27.1 5.37.3 VPI-VCI in VPI-VCI out 7.33.4 7.43.3 A B C 1 2 3

32. © 2000 B. Stiller, B. Plattner ETHZ-TIK, D. Bauer IBM Research CM III – 32 ETH Zürich ATM Layer – UNI Cell Format o GFC: Generic Flow-Control used at the service interface. o PT: Payload Type defines contents of a cell: User data congested, User data non-congested, Operation And Maintenance (OAM) cells, and Resource management cells. o CLP: Cell Loss Priority to identify low/high priority cells. o HEC: Header Error Control. GFC VPI VCI HEC VPI VCI PT CLP 1234512345 1 2 3 4 5 6 7 8 bit Byte Header Payload 5 Byte48 Byte UNI: User-Network Interface

33. © 2000 B. Stiller, B. Plattner ETHZ-TIK, D. Bauer IBM Research CM III – 33 ETH Zürich ATM Layer – NNI Cell Format o VPI: Virtual Path Identifier comprises of 12 bit length. o PT: Payload Type defines contents of a cell: User data congested, User data non-congested, Operation And Maintenance (OAM) cells, and Resource management cells. o CLP: Cell Loss Priority to identify low/high priority cells. o HEC: Header Error Control. VPI VCI VPI VCI HEC VCI PT CLP 1234512345 1 2 3 4 5 6 7 8 bit Byte Header Payload 5 Byte48 Byte NNI: Network-Network Interface

34. © 2000 B. Stiller, B. Plattner ETHZ-TIK, D. Bauer IBM Research CM III – 34 ETH Zürich Structure of the AAL o AAL includes sublayers: Segmentation and Reassembly (SAR) between packets/cells. Convergence sublayer (CS) for service- dependent adaptation: –Common Part Con- vergence Sublayer (CPCS) and –Service Specific Con- vergence Sublayer (SSCS). Layers may be empty. CS-1 SAR-1 AAL 1 SSCS-2 CPCS-2 SAR-2 AAL 2 SSCS-3/4 CPCS-3/4 SAR-3/4 AAL 3/4 SSCS-5 CPCS-5 SAR-5 AAL 5 ATM Adaptation Layer ATM Layer Class AClass BClass C/D

35. © 2000 B. Stiller, B. Plattner ETHZ-TIK, D. Bauer IBM Research CM III – 35 ETH Zürich AAL Comparison AAL 1 AAL Service Class Message Delimiter Advanced Buffer Allocation Multiplexing CS Padding CS Protocol Overhead CS Checksum SAR Payload SAR Protocol Overhead SAR Checksum CriteriaAAL 3/4AAL 5 AAL 2 A no 0 no 46/47 Byte 1/2 Byte no B no yes 0/46 Byte 2 Byte no 1/47 Byte 3 Byte no C/D BTAG yes 4 Byte 8 Byte no 44 Byte 4 Byte 10 bit C/D Bit in PTI no 0/47 Byte 8 Byte 32 bit 48 Byte 0 no PTI: Payload Type Information

36. © 2000 B. Stiller, B. Plattner ETHZ-TIK, D. Bauer IBM Research CM III – 36 ETH Zürich ATM Functions per Layer – Summary Layer AAL ATM PHY Subl. CS SAR TC PM Function Handles transmission errors Handles lost and misinserted cell conditions Handles timing between source and destination Handles cell delay variation Segments higher-layer information into 48 Byte fields Reassembles cell payload in higher layer information Multiplexes cells from different ATM channels Generates cell header (first four bytes) Performs payload type discrimination Performs traffic shaping and flow control Routes and switches cells as needed Indicates cell loss priority and selects cells for discarding HEC header sequence generation and verification Cell delineation Transmission frame generation and recovery Bit timing

37. © 2000 B. Stiller, B. Plattner ETHZ-TIK, D. Bauer IBM Research CM III – 37 ETH Zürich Part II: Overview of Technologies, ATM, and IP Overview of Networking Technologies – Developments – High-speed Characteristics – Switching Techniques ATM (Asynchronous Transfer Mode) – Principles of Cell Switching – ATM Connection Management – ATM Layer and Adaptation Layer IP (Internet Protocol) – Key Elements – Protocol Stack

38. © 2000 B. Stiller, B. Plattner ETHZ-TIK, D. Bauer IBM Research CM III – 38 ETH Zürich IP Technology o Key elements of the technology used in the Internet: Packet switching, using datagrams No connection-dependent state information in the network Distributed management Many physical subnetwork technologies One network protocol Two transport protocols Infrastructure for hundreds of different distributed applications Scalability: to accommodate exponential growth

39. © 2000 B. Stiller, B. Plattner ETHZ-TIK, D. Bauer IBM Research CM III – 39 ETH Zürich IP Protocol Stack Phys. Network layer Internet layer Application layer EthernetDECnetATM HTTPDNSFTP IP TCPUDP Transport layer Routing

40. © 2000 B. Stiller, B. Plattner ETHZ-TIK, D. Bauer IBM Research CM III – 40 ETH Zürich Internet Protocol (IP) o IPv4 shows addressing problems: Nearly exhausted Class B addresses. Classless Inter- domain Routing (CIDR) provides short-term solution only. Routing tables grow extremely fast. IP unicast address space will run out due to radipdly, e.g., increasing Internet hosts and low-end Internet devices. o Next Generation Internet, IPv6, delivers solutions: Extended addressing: 128 bit addresses. Address hierarchy levels (hierarchy: subscriber, subnet,...) Anycast addresses to reach the “nearest” node of a group (in terms of the routing metric). Simplified IP header, including a flow label.

41. © 2000 B. Stiller, B. Plattner ETHZ-TIK, D. Bauer IBM Research CM III – 41 ETH Zürich Internet Network Model International ISP “Backbone” Regional ISP B Large Enterprise Small Enterprise ISP: Internet Service ProviderSOHO: Small Office and Home SOHO

42. © 2000 B. Stiller, B. Plattner ETHZ-TIK, D. Bauer IBM Research CM III – 42 ETH Zürich Example – Backbone ISP: UUNET http://www.caida.org/Tools/Mapnet/Backbones/

43. © 2000 B. Stiller, B. Plattner ETHZ-TIK, D. Bauer IBM Research CM III – 43 ETH Zürich Example – Regional ISP: Switch http://www.switch.ch

44. © 2000 B. Stiller, B. Plattner ETHZ-TIK, D. Bauer IBM Research CM III – 44 ETH Zürich Switch – UUNET Interconnection http://www.switch.ch

45. © 2000 B. Stiller, B. Plattner ETHZ-TIK, D. Bauer IBM Research CM III – 45 ETH Zürich Co-location Model o Extensions broadens the model by other services: More than a pure routing and traffic exchange role. Content provider supported, e.g., with high volumes, selection of non-local transit providers. E.g., Multicast, Web, DNS, policy-based route services. Router Multicast Router Route Server Web Server DNS Server

46. © 2000 B. Stiller, B. Plattner ETHZ-TIK, D. Bauer IBM Research CM III – 46 ETH Zürich Services Integrated Internet QoS Guarantees Configuration Zone State Information Required Protocols Status Best-effortIntServDiffServ no none entire network none operational per data stream per session (dynamic) end-to-end data stream per data stream, in router signaling (RSVP) matured aggregated log-term (static) domain- oriented (none, in BB, in edge router) bit fields (BB, COPS) worked on IntServ: Integrated Services, DiffServ: Differentiated Services, QoS: Quality-of-Service RSVP: Resource Reservation Protocol, BB: Bandwidth Broker, COPS: Common Open Policy Service

47. © 2000 B. Stiller, B. Plattner ETHZ-TIK, D. Bauer IBM Research CM III – 47 ETH Zürich IntServ Implementation o Integrated Services Architecture (IntServ) supports best-effort and guaranteed services. o Traffic control functions: Admission control, Packet classifier, and Packet scheduler. Optional: Policy control (COPS). o Protocol support: Resource reservation, E.g., RSVP (Resource Reservation Protocol). o Host and router require similar functionality. Policy Control Resource Reservation Application Admission Control Packet Classifier Packet Scheduler Control Data

48. © 2000 B. Stiller, B. Plattner ETHZ-TIK, D. Bauer IBM Research CM III – 48 ETH Zürich The DiffServ Approach o Requirements for Differentiated Services proposals: Aggregated bandwidth allocation without the need of per-session signaling and complex router state, Aggregated QoS guarantees with edge-complexity, Long-term service contracts within a single domain, Integrated and simplified accounting, Better traffic isolation for performance predictability, and Better services for users willing to pay more. o A set of new proposals for DiffServ: Expedited Forwarding (EF) and Assured Forwarding (AF).

49. © 2000 B. Stiller, B. Plattner ETHZ-TIK, D. Bauer IBM Research CM III – 49 ETH Zürich DiffServ Implementation

50. © 2000 B. Stiller, B. Plattner ETHZ-TIK, D. Bauer IBM Research CM III – 50 ETH Zürich References (1) F. Fluckiger: Understanding Networked Multimedia; Prentice Hall, London, England, 1995, ISBN 0–13–190992–4. R. Steinmetz: Multimedia Technologie; Springer Verlag, Bonn, Germany, 1999, ISBN 3-540-62060-5. M. de Prycker: Asynchronous Transfer Mode – Solution for Broadband ISDN; 3rd Edition, Prentice Hall, Englewood Cliffs, New Jersey, U.S.A., 1995, ISBN 0–13–342171–6. ITU-T – Maintenance Principles: Frame Relay Operation and Maintenance Principles and Functions; I.620, October 1996.

51. © 2000 B. Stiller, B. Plattner ETHZ-TIK, D. Bauer IBM Research CM III – 51 ETH Zürich References (2) R. J. Vetter: ATM Concepts, Architectures, and Protocols; Communications of the ACM, Vol. 38, No. 2, February 1995, pp 30 – 38. B. G. Kim, P. Wang: ATM Network: Goals and Challenges; Com. of the ACM, Vol. 38, No. 2, February 1995, pp 39 – 44. M. de Prycker: Asynchronous Transfer Mode – Solution for Broadband ISDN; 3rd Edition, Prentice Hall, Engle-wood Cliffs, New Jersey, U.S.A., 1995, ISBN 0–13–342171–6. T. Braun: Die Internet-Protokollfamilie der nächsten Generation; Praxis der Informationsverarbeitung und Kommunikation, Vol. 19, No. 2, 1996, pp 94 – 102. X. Xiao, L. M. Ni: Internet QoS: A Big Picture; IEEE Network Magazine, Vol. 13, March/April 1999, pp 8 – 18.