GMPLS networks and optical network testbeds. Malathi Veeraraghavan

Transcription

1 GMPLS networks and optical network testbeds Malathi Veeraraghavan Professor Charles L. Brown Dept. of Electrical & Computer Engineering University of Virginia Tutorial at ICACT09 Feb GMPLS: Generalized MultiProtocol Label Switched networks (MPLS, SONET, WDM, SDM, VLAN) 1 Outline Principles Different types of connection-oriented networks Technologies Single network Internetworking Usage Commercial networks Research & Education Networks (REN) 2 1

2 Principles Types of switches and networks Bandwidth sharing modes TCP in connectionless (IP) networks Immediate-request and book-ahead modes in connection-oriented networks 3 Types of switches Multiplexing technique on data-plane links Admission control in control plane? Connectionless (CL) - no admission control Circuit switch (CS) - position based (port, time, lambda) Not an option Packet switch (PS) - header based e.g., Ethernet Connection-oriented (CO) - admission control e.g., telephone SONET WDM Virtual-circuit e.g., MPLS, ATM 4 2

3 Types of networks Support function Network type Addressing (in data or control plane?) Routing Connectionless (CL) Data plane Signaling Circuit Switched (CS) Virtual circuit (VC) Control plane Control plane Connection-oriented 5 How is bandwidth shared on a connectionless packet-switched network? Pre-1988 IP network: Just send data without reservations or any mechanism to adjust rates congestion collapses! Van Jacobson's 1988 contribution: Added congestion control to TCP Sending TCP adjusts rate Advantages: Proportional fairness High utilization Disadvantages: No rate guarantees No temporal fairness (job seniority) 6 3

4 TCP throughput B= RTT 1 2bp 3bp + T min(1,3 ) ( p + p ) 3 8 B: Throughput in congestion-avoidance phase RTT: Round-trip time b: an ACK is sent every b segments (b is typically 2) p: packet loss rate on path T 0 : initial retransmission time out in a sequence of retries Effective rate = min (r,b) r: bottleneck link rate Padhye, Firoui, Towsley, Kurose, ACM Sigcomm 98 paper 7 TCP throughput Case Packet loss rate Input parameters Bottleneck link rate Round-trip delay Mean transfer delay for a 1GB file (s) Case Mb/s 0.1ms Case 2 Case 3 Case 4 1Gbps 5ms 50ms 0.1ms ~21Mbps Case 5 5ms 39.6 Case 6 50ms Case 7 Case Mbps 0.1ms 5ms Case 9 50ms 1293 Case 10 1Gbps 0.1ms 8.64 Case 11 5ms Case 12 50ms 1287 Case 13 Case 14 Case 15 Case Mbps 1Gbps 0.1ms 5ms 50ms 0.1ms ~2Mbps Case 17 Case 18 5ms 50ms

5 Bandwidth sharing in circuit networks (immediate-request mode) Key difference: Admission control Intrinsic to circuit networks: position based mux Send a call setup request: if requested bandwidth is available, it is allocated to the call if not, the call is blocked (rejected) M/G/m/m model: m: number of circuits 9 λ ρ = µ Pb ub ErlangB formula m ρ / m! = m k ρ / k! k= 0 (1 Pb ) ρ = m ρ: offered traffic load in Erlangs λ: call arrival rate 1/µ: mean call holding time m: number of circuits P b : call blocking probability u b : utilization For a 1% call blocking probability, i.e., P b = 0.01 ρ m u a % 58.2% 84.6% If m is small, high utilization can only be achieved along with high call blocking probability 10 5

6 Needed if per-call circuit rate is a large fraction of link capacity (e.g., 1Gbps circuits on a 10Gbps link, m = 10) Bandwidth sharing mechanisms in CO networks Book-ahead call duration specified Bandwidth sharing mechanisms Immediate-request unspecified call duration BA-n/BA-First session-type requests BA-n Users specify a set of call-initiation time options BA-First Users are given first available timeslot VBDS (Varying-Bandwidth Delayed Start) data-type requests X. Zhu, Ph.D. Thesis, UVA, 11 Comparison of Immediate-Request (IR) and Book-Ahead (BA) schemes Example To achieve a 90% utilization with a call blocking probability less than 10% BA-First schemes are needed when m < 59 To achieve a 90% utilization with a call blocking probability less than 20% BA-First schemes are needed when m < 32 U: utilization K: number of time periods in advance-reservation window IR m=10, U = 80%: P B = 23.6% m=100, U = 80%: P B = 0.4% BA m=10, K=10, U = 80%: P B = 0.4% 12 6

7 Virtual circuit (VC) networks Bandwidth sharing more complex, but better utilization PLUS service guarantees Call Admission Control Needed in circuit networks Scheduling (example: weighted fair queueing) Traffic shaping/policing (example: leaky-bucket algorithm) Two additional dimensions in VC networks 13 Outline Principles Different types of connection-oriented networks Technologies Single network Internetworking Usage Commercial networks Research & Education Networks (REN) 14 7

8 Technologies GMPLS networks Data-(user-) plane protocols packet-switched: MPLS, VLAN Ethernet circuit-switched: SONET/SDH, WDM, SDM (space div. mux) Control-plane protocols: RSVP-TE: signaling protocol OSPF-TE: routing protocol LMP: link management protocol Internetworking GFP, VCAT, LCAS for SONET/SDH PWE3 for MPLS networks Digital wrapper for OTN 15 Multiprotocol label switching (MPLS) MPLS Header Label Value CoS S TTL 20 Bits MPLS Header: Label Value: Label used to identify the virtual circuit Class of Service (CoS): Experimental field, Used for QoS support S: Identifies the bottom of the label stack TTL: Time-To-Live value Virtual circuits: Label Switched Path (LSP) 8

9 IEEE 802.1Q Ethernet VLAN new fields Dest. MAC Address Source MAC Address TPID TCI Type /Len Data FCS FCS: Frame Check Sequence 2 Bytes VLAN Tag User 802.1Q Tag Type CFI Priority VLAN ID 3 Bits 1 Bit 12 Bits VLAN Tag Fields Tag Protocol Identifier (TPID) 802.1Q Tag Protocol Type set to 0x8100 to identify the frame as a tagged frame Tag Control Information (TCI) User Priority As defined in 802.1p, 3 bits represent eight priority levels CFI Canonical Format Indicator, set to indicate the presence of an Embedded-RIF VLAN ID Uniquely identifies the frame's VLAN 9

10 SONET/SDH rates (number is the multiplier) Example: STS-48 frame has 48 x 90 columns in 125 µs STS-1: 90 columns by 9 rows in 125µs 19 Tanenbaum Optical transport networks (OTN) G. 872 layers OTS: Optical Transmission Section OMS: Optical Multiplex Section OCh: Optical Channel G.709: Technique for mapping client signals onto the Optical Channel via layers: OTU: Optical Channel Transport Unit, and ODU: Optical Channel Data Unit 20 10

11 Layers within an OTN 21 Courtesy: T. Walker's tutorial OTN Hierarchy Low layer Higher layers Electrical domain: OTU: Optical Channel Transport Unit ODU: Optical Channel Data Unit OPU: Optical Channel Payload Unit 22 Courtesy: T. Walker's tutorial 11

12 G. 709 Optical Channel frame structure (digital wrapper) OCh overhead OCh payload FEC Optical channel (OCh) overhead: support operations, administration, and maintenance functions OCh payload: can be STM-N, ATM, IP, Ethernet, GFP frames, OTN ODUk, etc. FEC: Reed-Solomon RS(255, 239) code recommended; roughly introduces a 6.7% overhead Frame size: 4 rows of 4080 bytes Frame period: OTU µs (payload data rate: roughly Gbps ) OTU µs (payload data rate: roughly Gbps ) OTU µs (payload data rate: roughly Gbps ) 23 GMPLS networks Technologies Data-(user-) plane protocols packet-switched: MPLS, VLAN Ethernet, Intserv IP circuit-switched: SONET/SDH, WDM, SDM Control-plane protocols: RSVP-TE: signaling protocol OSPF-TE: routing protocol LMP: link management protocol Internetworking GFP, VCAT, LCAS for SONET/SDH PWE3 for MPLS networks Digital wrapper for OTN 24 12

13 The evolution of Resource reservation Protocol (RSVP) RSVP (RFC2205, 1997) RSVP-TE (RFC 3209, 2001) RSVP-TE GMPLS Extension (RFC 3471, 3473, 2003) RSVP-TE GMPLS Extension for SONET/SDH (RFC 3946, 2004, RFC 4606, 2006) 25 Purpose of signaling (needed only in CO networks) Functions: Call setup: Route selection Admission control: sufficient bandwidth? Switch fabric configuration of each switch recall position based multiplexing Call release release bandwidth for use by others 26 13

14 Circuit-switched networks Phase 1: Routing protocol exchanges + routing table precomputation Host I-A I II Dest. III-B III-C III Next hop III-B III-C Host III-B Dest. III-* Next hop IV IV Dest. Next hop III-* III V Host III-C Routing protocols exchange: topology address reachability loading conditions 27 Circuit-switched networks Phase 2: Signaling for call setup Routing table Connection setup (Dest: III-B; BW: OC1; Timeslot: a, 1) Host I-A Dest. III-* a I b Next hop IV c a b II IV c d a III d c b V Host III-B Connection setup actions at each switch on the path: 1. Parse message to extract parameter values 2. Lookup routing table for next hop to reach destination 3. Read and update CAC (Connection Admission Control) table 4. Select timeslots on output port 5. Configure switch fabric: write entry into timeslot mapping table 6. Construct setup message to send to next hop 28 14

15 Routing table CAC table Host I-A Timeslot mapping table Circuit-switched networks Phase 2: Signaling for call setup Connection setup (Dest: III-B; BW: OC1; Timeslot: a, 1) Dest. III-* Next hop a I b Next hop IV c Interface (Port); Capacity; Avail timeslots IV c; OC12; 1, 4, 5 INPUT Port /Timeslot OUTPUT Port/Timeslot a/1 c/1 Connection setup a b II IV c d a III d c Host III-B Connection setup actions at each switch on the path: 1. Parse message to extract parameter values 2. Lookup routing table for next hop to reach destination 3. Read and update CAC (Connection Admission Control) table 4. Select timeslots on output port 5. Configure switch fabric: write entry into timeslot mapping table 6. Construct setup message to send to next hop b V Update to remove timeslot 1 from available list 29 Circuit-switched networks Phase 2: Signaling for call setup II Host I-A Connection setup (Dest: III-B; BW: OC1; Timeslot: a, 1) Time slot could be different on each hop a I b c a b IV Connection setup c d INPUT Port /Timeslot a OUTPUT Port/Timeslot a/1 c/2 Perform same set of 6 connection setup steps at switch IV write timeslot mapping table entry, update CAC table and send connection setup message to the next hop III d c b V Host III-B 30 15

16 Circuit-switched networks Phase 2: Signaling for call setup Host I-A a I b c a b II IV Connection setup c d a III d INPUT Port /Timeslot Perform same set of 6 connection setup steps at switch III c b V OUTPUT Port/Timeslot d/2 b/1 Host III-B Connection setup Circuit setup complete Reverse setup-confirmation messages typically sent from destination through switches to source host 31 Circuit-switched networks Phase 3: User-data flow Host I-A 1 2 IN Port /Timeslot a I a/1 c/1 b c OUT Port/Timeslot II a b IV c IN Port /Timeslot d OUT Port/Timeslot a IN Port /Timeslot III d V c b OUT Port/Timeslot d/2 b/1 1 2 Host III-B a/1 c/2 Bits arriving at switch I on time slot 1 at port a are switched to time slot 1 of port c 32 16

17 Release procedure When a communication session ends, there is a hop-by-hop release procedure (similar to the setup procedure) to release timeslots/wavelengths for use by new calls 33 RSVP messages and parameters Messages: Setup: Path (forward) and Resv (reverse) Release: PathTear, ResvTear Parameters Destination: SESSION object Bandwidth: Sender Tspec object or SONET/SDH Tspec Timeslot/Wavelength: Generalized LABEL for ports, wavelengths SUKLM label for SONET/SDH Only supports immediate-request circuits/virtual circuits No time-dimension parameters for book-ahead 34 17

18 Explicit Route Object (ERO) A list of groups of nodes along the explicit route (generically called "source route") Thinking: source routing is better for calls than hop-by-hop routing as it can take into account loading conditions Constrained shortest path first (CSPF) algorithm executed at the first node to compute end-to-end route, which is included in the ERO 35 Control-plane message transport: inband or out-of-band Separation of control plane from data plane in GMPLS networks - out-of-band IP router Internet IP router Control-plane messages Ethernet control ports SONET or WDM switch GMPLS Network Ethernet control ports SONET or WDM switch Circuit established Data-plane link 36 18

19 Interface ID field Control plane separation: Requires upstream switch to identify on which data-plane interface the virtual circuit should be routed Interface ID field defined in the tag-length-value format Embedded within the RSVP-HOP object Carried in PATH messages 37 Technologies GMPLS networks Data-(user-) plane protocols packet-switched: MPLS, VLAN Ethernet, Intserv IP circuit-switched: SONET/SDH, WDM, SDM Control-plane protocols: RSVP-TE: signaling protocol OSPF-TE: routing protocol LMP: link management protocol Internetworking GFP, VCAT, LCAS for SONET/SDH PWE3 for MPLS networks Digital wrapper for OTN 38 19

20 OSPF-TE: Open Shortest Path First -Traffic Engineering To advertise loading conditions New parameters: Maximum bandwidth of a link Maximum reservable bandwidth: can be greater than the maximum bandwidth to support oversubscription Unreserved bandwidth RFC for MPLS networks Only supports immediate-request circuits/virtual circuits No time-dimension parameters for book-ahead 39 OSPF-TE extensions for GMPLS RFC 4202 and 4203 Main new parameters Shared Risk Link Group Interface Switching Capability Descriptor (ISCD) Allows multiple types of switching techniques Example for SONET: Minimum LSP Bandwidth: OC1 on a SONET interface if the switch demultiplexes down to OC1 level 40 20

21 Difference between labels in MPLS and circuit-switched GMPLS In circuit-switched GMPLS networks, labels are not carried in the data plane Labels in circuit-switched networks identify "position" of data for the circuit - time or wavelength In circuit-switched GMPLS networks, cannot assign labels without associated bandwidth reservation In usage section, we will see the value of this feature in MPLS networks See two applications: traffic engineering, VPLS (addressing benefits) 41 Technologies GMPLS networks Data-(user-) plane protocols packet-switched: MPLS, VLAN Ethernet, Intserv IP circuit-switched: SONET/SDH, WDM, SDM Control-plane protocols: RSVP-TE: signaling protocol OSPF-TE: routing protocol LMP: link management protocol Internetworking GFP, VCAT, LCAS for SONET/SDH PWE3 for MPLS networks Digital wrapper for OTN 42 21

22 LMP procedures Control channel management Set up and maintain control channels between adjacent nodes Link property correlation Aggregate multiple data links into a TE link Synchronize TE link properties at both ends Link connectivity verification (optional) Data plane discovery; If_Id exchange; physical connectivity verification Fault management (optional) Fault notification and localization Reference: IETF RFC Control-plane security Need authentication and integrity for all control-plane exchanges Since RSVP, OSPF, LMP run over IP, IPsec is a possible solution 44 22

23 Technologies GMPLS networks Data-(user-) plane protocols packet-switched: MPLS, VLAN Ethernet, Intserv IP circuit-switched: SONET/SDH, WDM, SDM Control-plane protocols: RSVP-TE OSPF-TE LMP Internetworking GFP, VCAT, LCAS for SONET/SDH PWE3 for MPLS networks Digital wrapper for OTN 45 Why internetworking? GMPLS networks do not exist as standalone entities Instead they are part of the Internet: Obvious usage: to interconnect IP routers Newer uses: Commercial: interconnect Ethernet switches in geographically distributed LANs via point-to-point links or VPNs Research & Education networks: connect GbE and 10GbE cards on cluster computers and storage devices to GMPLS networks 46 23

24 Obvious usage Router-to-router circuits and virtual circuits IP router Internet IP router GMPLS Network SONET or WDM switch SONET or WDM switch 47 Router-to-router usage OSPF-enabled usage simply treat MPLS virtual circuit or GMPLS circuit as a link between routers allow routing protocol to include these in routing table computations Data-plane IP over MPLS IP over PPP over SONET Packet-over-SONET (PoS) 48 24

25 Newer uses New type of gateway functionality No IP layer involvement Instead Ethernet frames are mapped onto MPLS virtual circuits or GMPLS circuits port mapped VLAN mapped Cisco and Juniper routers support Ethernet over MPLS Sycamore and Ciena SONET switches support Ethernet over GMPLS 49 Ethernet port mapped over MPLS SDM-to-MPLS gateway IP router/mpls switch I Internet Pseudowire SDM-to-MPLS gateway IP router/mpls switch II Ethernet switch MPLS LSP (virtual circuit) Mux scheme on pseudowire: Ethernet Ethernet switch Enterprise 1 Gateway: interfaces have different MUX schemes Enterprise 2 unlike switch, which has same MUX scheme on all links Send all Ethernet frames received on ports I and II on to the MPLS LSP MPLS LSP: Pseudo-wire Enterprise can allocate IP addresses from one subnet: Virtual Private LAN Service (VPLS) Explains one use for MPLS virtual circuits with no bandwith allocation 50 SDM: Space Division Multiplexing 25

26 Ethernet VLAN mapped over MPLS VLAN-to-MPLS gateway IP router/mpls switch I Internet VLAN-to-MPLS gateway IP router/mpls switch II Ethernet switch MPLS LSP Ethernet switch Enterprise 1 Enterprise 2 Extract frames carrying a specific VLAN ID tag on Ethernet ports I and II and map only these frames on to the MPLS LSP 51 Ethernet port or VLAN mapped over GMPLS circuits SDM-to-SONET/WDM gateway SDM-to-SONET/WDM gateway SONET or WDM switch SONET or WDM switch I II Ethernet switch SONET/SDH/WDM circuit Ethernet switch Enterprise 1 Enterprise 2 Send all frames or frames matching a given VLAN ID tag from Ethernet ports I and II on to the SONET/SDH/WDM circuit SONET/SDH/WDM switches now have Fast Ethernet/GbE/10GbE interfaces in addition to SONET/SDM or WDM interfaces 52 26

27 Commercial services EPL: Ethernet private line: map an Ethernet port to a SONET/SDH circuit Fractional-EPL: Map a GbE port to a lowerrate SONET circuit Pause frames sent from switch to client node if buffer fills up V-EPL: Lower-rate VLAN mapped to an equivalent-rate SONET circuit MetroEthernet Forum: E-Line and E-LAN page 110 of GFP section reference: SONET focused 53 Technology So what technologies are required for this type of internetworking: mapping Ethernet frames on to MPLS/GMPLS virtual circuit/circuit mapping? 54 27

28 Technologies GMPLS networks Data-(user-) plane protocols packet-switched: MPLS, VLAN Ethernet, Intserv IP circuit-switched: SONET/SDH, WDM, SDM Control-plane protocols: RSVP-TE OSPF-TE LMP Internetworking GFP, VCAT, LCAS for SONET/SDH PWE3 for MPLS networks Digital wrapper for OTN 55 Why do we need Generic Framing Procedure (GFP)? The framing techniques used in other data-link layer protocols have problems For example, IP packets are carried over SONET using PPP/HDLC frames (called PoS) HDLC inserts idle frames because SONET is synchronous it needs a constant flow of frames to avoid losing synchronization But, there is a problem: HDLC uses flags for frame delineation. The issue with this framing technique is that if the flag pattern occurs in the payload, an escape byte has to be inserted This causes an increase in the required bandwidth The amount of increase is payload-dependent page 98 of reference 56 28

29 Other framing techniques HEC - Header Error Control this is the CRC framing technique used in ATM "A header CRC hunting mechanism is employed by the receiver to extract the ATM cells from the bit/byte synchronous stream. The HEC location is fixed and ATM cell length is fixed. Starting from the assumed cell boundary, the ATM receiver compares its computed HEC value for the assumed ATM cell header against the HEC value indicated by the assumed HEC field. Cell stream delineation is declared after positive validations of the incoming HEC fields of a few consecutive ATM cells." ATM cells are fixed in length, but Ethernet frames are variable-length Therefore, we need a length field in order to implement this HEC-based frame delineation mechanism pages of reference 57 Main features of the GFP protocol Common aspects (applicable to all client signals): HEC + Length based delineation Core header has payload length and HEC Error control: error detection Payload type HEC, payload Frame Check Sequence (CRC-32) Multiplexing: linear and ring extension headers Idle frames are sent to maintain synchronization as in HDLC Scrambling as in ATM: core header + payload scrambling Client management - client fail signal Client-dependent aspects: Client-specific encapsulation techniques page 68 of reference 58 29

30 Virtual Concatenation (VCAT) for increased efficiency Data signal SONET/SDH payload mapping and bandwidth efficiency SONET/SDH with VCAT payload mapping and bandwidth efficiency Ethernet (10 Mb/s) STS-1/VC-3 21% VT1.5-7v/VC-11-7v 89% Fast Ethernet (100 Mb/s) STS-3c/VC-4 67% VT1.5-64v/VC-11-64v 98% Gigabit Ethernet (1000 Mb/s) STS-48c/VC-4-16c 42% STS-3c-7v/VC-4-7v 95% STS-1-21v/VC-3-21v 98% Page 75 of reference 59 Inverse multiplexing in VCAT Implementation of VCAT is only required at select nodes (i.e., the edge nodes); not all multiplexers need to support VCAT Page 82 of reference 60 30

31 Link Capacity Adjustment Scheme (LCAS) LCAS is a mechanism to allow for automatic bandwidth tuning of a virtually concatenated signal The VCAT group of circuits should already be established using a centralized NMS/EMS based procedure, or by a distributed RSVP-TE based procedure Note that bandwidth cannot be increased beyond the aggregate value of the VCAT signal without a GMPLS RSVP or NMS/EMS procedure of circuit setup 61 Link Capacity Adjustment Scheme (LCAS) LCAS is a synchronization procedure between the two ends of a VCAT signal Unlike GMPLS RSVP, it is NOT a bandwidth reservation and circuit setup or release procedure LCAS procedures (triggered by GMPLS or NMS/EMS): add or remove a member of a VCAT group renumber the members in a VCAT group Messages are exchanged between the originating and terminating SONET/SDH nodes to execute these LCAS procedures Add member (ChID, GID) Remove member (ChID, GID) Member status Messages are sent in the H4 byte for high-order VCAT 62 31

32 Technologies GMPLS networks Data-(user-) plane protocols packet-switched: MPLS, VLAN Ethernet, Intserv IP circuit-switched: SONET/SDH, WDM, SDM Control-plane protocols: RSVP-TE OSPF-TE LMP Internetworking GFP, VCAT, LCAS for SONET/SDH PWE3 for MPLS networks Digital wrapper for OTN 63 Pseudo Wire Emulation Pseudo Wire Emulation Edge-to-Edge (PWE3) is a mechanism for emulating certain services across a packet-switched network: Services: Frame-relay, ATM, Ethernet, TDM services, such as SONET/SDH Packet-switched network: IP MPLS Common usage: Ethernet service over MPLS Port-mapped to MPLS LSP VLAN mapped to MPLS LSP IETF RFC

33 Digital wrapper ITU-T G. 709 provides a method to carry Ethernet frames, ATM cells, IP datagrams directly on a WDM lightpath 65 Outline Principles Different types of connection-oriented networks Technologies Single network Internetworking Usage Commercial networks Research & Education Networks (REN) 66 33

34 Commercial uses Semi-permanent MPLS virtual circuits Traffic engineering Voice over IP QoS concerns: telephony has a 150ms oneway delay requirement (with echo cancellers) Business or service provider interconnect interconnecting geographically distributed campuses of an enterprise interconnecting wide-area routers of an ISP service provider 67 Traffic engineering (TE) Since BGP and OSPF routing protocols mainly spread reachability information, routing tables are such that some links become heavily congested while others are lightly loaded MPLS virtual circuits are used to alleviate this problem e.g., NY to SF traffic could be directed to take an MPLS virtual circuit on a lightly loaded route avoiding all paths on which more local traffic may compete This is an application of MPLS VCs without bandwidth allocation 68 34

35 Goals of Traffic Engineering (TE) Monitor network resources and control traffic to maximize performance objectives Goal of TE is to achieve efficient network operation with optimized resource utilization in an Autonomous System Goals of TE can be: Traffic oriented Enhance the QoS of traffic streams Minimization of loss and delay Maximization of throughput Resource oriented Load balancing Minimize maximum congestion or minimize maximum resource utilization Output decreased packet loss and delay, increased throughput 69 Business or service provider interconnect Multiple options: TDM circuits (traditional private line, T1, T3, OC3, OC12, etc.) Ethernet private line point-to-point (Ethernet over MPLS/SONET/WDM) VPNs (called Virtual private LAN service) MPLS VPNs WDM lightpaths Dark fiber 70 35

36 Dynamic circuits/virtual circuit (GMPLS control-plane) Commercial: fast restoration circuit/vc setup delay significant rapid provisioning Verizon: Bandwidth on Demand (Just-in-Time Provisioning) AT&T: Shared mesh networks Customer Applications for dynamic network configuration» Key industries: Financial, Media & Entertainment» Corporate Utility Backbone Networks (e.g. reconfigure for disaster recovery)» Distribution of real-time content (e.g., Video) Level3: Vyvx service 71 Research & Education (G)MPLS networks Internet2 s Dynamic Circuit network NSF-funded DRAGON DOE's ESnet - Science Data Network DOE's Ultra Science Network (USN) NSF-funded CHEETAH 72 36

37 Internet2 DWDM network Infinera DWDM system Rick Summerhill talk (10/11/2007) Internet2 Dynamic Circuit (DC) network Ciena CD-CI Eth-SONET switch Rick Summerhill talk (10/11/2007) 37

38 Internet2 IP-routed network IP-router-to-router links on one wavelength SONET switch-to-switch links on another wavelength Ciena CD-CI Eth-SONET switch Juniper T640 IP router Rick Summerhill talk (10/11/2007) Equipment at each PoP Rick Summerhill talk (10/11/2007) 38

39 Control-plane software (for DC network) OSCARS implemented in InterDomain Controller (IDC) - one per domain Abstracted topology exchange Interdomain scheduling Interdomain signaling (for provisioning) DRAGON (intradomain control-plane) Used in Internet2 s DC network Intradomain routing, path computation, signaling (for provisioning) 77 OSCARS On-demand Secure Circuits and Advance Reservation System (OSCARS) DOE Office of Science and ESnet project Co-development with Internet2 Web Service based provisioning infrastructure, which includes scheduling, AAA architecture using X.509 certificates Extended to include the DICE IDCP Reservations held in SQL database Recall no support for book-ahead in GMPLS control protocols Talk by Tom Lehman, Sep. 28,

40 DRAGON Washington DC metro-area network: Adva (old Movaz) WDM switches and Ethernet switches (G.709) Control-plane software: Network Aware Resource Broker NARB Intradomain listener, Path Computation Virtual Label Swapping Router VLSR Implements OSPF-TE, RSVP-TE Run on control PCs external to switches (since not all switches implement these GMPLS control-plane protocols) Communicates with switches via SNMP, TL1, CLI to configure circuits. Client System Agent CSA End system software for signaling into network (UNI or peer mode) Application Specific Topology Builder ASTB User Interface and processing which build topologies on behalf of users Topologies are a user specific configuration of multiple LSPs 79 Open Source DCN Software Suite OSCARS (IDC) Open source project maintained by ESNet and Internet2 Uses WDSL, XML, SQL database to store reservations Reservations accepted with 1 minute granularity DRAGON (DC) NSF-funded Open source project maintained by USC ISI EASTand MAX Version 0.4 of DCNSS current deployed release DCN workshops offered for training: Talk by Tom Lehman, Sep. 28,

41 DICE IDCP Dante, Internet2, CANARIE, ESNet IDCP: InterDomain Controller Protocol wsdl - web service definition of message types and formats xsd definition of schemas used for network topology descriptions and path definitions Talk by Tom Lehman, Sep. 28, InterDomain Controller (IDC) Protocol (IDCP) The following organizations have implemented/deployed systems which are compatible with this IDCP Internet2 Dynamic Circuit Network (DCN) ESNet Science Data Network (SDN) GÉANT2 AutoBahn System Nortel (via a wrapper on top of their commercial DRAC System) Surfnet (via use of above Nortel solution) LHCNet (use of I2 DCN Software Suite) Nysernet (use of I2 DCN Software Suite) LEARN (use of I2 DCN Software Suite) LONI (use of I2 DCN Software Suite) Northrop Grumman (use of I2 DCN Software Suite) University of Amsterdam (use of I2 DCN Software Suite) DRAGON Network The following "higher level service applications" have adapted their existing systems to communicate via the user request side of the IDCP: LambdaStation (FermiLab) CMS project on Large Hadron Collider TeraPaths (Brookhaven) - ATLAS project on Large Hadron Collider Phoebus Talk by Tom Lehman, Sep. 28,

42 Heterogeneous Network Technologies Complex End to End Paths Example: DRAGON AS 1 IP Control Plane Example: Internet2 DC Example: ESNet SDN AS 2 IP Control Plane AS 3 IP Control Plane VLSR VLSR End System Ethernet Segment VLSR Established VLAN Ethernet over WDM Ethernet over SONET Ethernet Lambda Switch SONET Switch Router Router MPLS LSP End System Ethernet Segment VLSR Established VLAN Rick Summerhill talk (10/11/2007) IDCP operation Route selection, admission control centralized per domain at IDC Advance reservation request and circuit provisioning at scheduled time: End user signals IDC with a reservation request Authenticate requester and check authorization Request reservation (create time, bandwidth, VLAN tag) Signaling: creation of circuit (automatic or in response to message to IDC) Topology exchange: interdomain (abstracted topology information) Monitoring

43 Intra-domain operations Using DRAGON in Internet2 DCN NARB does intra-domain path computation after collecting routing information by listening to OSPF-TE exchanges between VLSRs These intradomain paths are provided to IDC for use during resource scheduling (upto 3 path options are considered) 5 VLSRs serve 22 CD-CIs: subnets of CD-CIs In Signaling phase, VLSR sends TL1 command to edge CD- CI, which initiates proprietary hop-by-hop signaling to configure circuit through subnet 85 GOLE: GLIF open lightpath exchange 86 43

44 DOE networks ESnet and Science Data Network (SDN) OSCARS: an advance-reservation system Science Data Network: MPLS network UltraScience Network Research network for DoE labs GbE and SONET (Ciena CD-CI) Centralized scheduler for advance-reservation calls 5-PoP network: ORNL, Atlanta, Chicago, Seattle, Sunnyvale Connections to Fermi Lab, PNNL, SLAC, CalTech Lambdastation: CMS project Between Fermi Lab and Univ. of Nebraska 87 NSF-funded CHEETAH network GbEthernet and SONET OC192 card TN PoP SN16000 Control card GbE/ 10GbE card GbE End hosts GbE UVa NCSU GbEs GbE CUNY OC-192 End hosts GbE GA PoP SN16000 GbE/ 10GbE card Control card OC192 cards OC192 card NC PoP SN16000 Control card GbE/ GbE 10GbE card End hosts ORNL GbE OC-192 Sycamore SN16000 SONET switch with GbE/10GbE interfaces GbE GaTech 88 44

45 Networking software Sycamore switch comes with built-in GMPLS control-plane protocols: RSVP-TE and OSPF-TE We developed CHEETAH software for Linux end hosts: circuit-requestor allows users and applications to issue RSVP-TE call setup and release messages asking for dedicated circuits to remote end hosts CircuitTCP (CTCP) code 89 CHEETAH network usage End Host CHEETAH software DNS client IP-routed network CHEETAH software DNS client End Host Application RSVP-TE module SONET circuitswitched network RSVP-TE module Application TCP/IP TCP/IP CTCP/IP NIC 1 NIC 2 Circuit Gateway Circuit Gateway NIC 1 NIC 2 CTCP/IP Bandwidth-sharing mode: Immediate-request mode Heterogeneous rate allocation under high loads: higher BW for large files than for small files Applications: Common file transfers (web, P2P, CDN, storage) attempts circuits for large files (if blocked, use IP-routed path) use IP-routed path for small files 90 45

46 End-to-end call setup delay measurements Delays incurred in setting up a circuit between host zelda1 (in Atlanta, GA) and host wuneng (in Raleigh, NC) across the CHEETAH network Circuit type End-to-end circuit setup delay (s) Processing delay for Path message at the NC SN16000 (s) Processing delay for Resv message at the NC SN16000 (s) OC OC Gb/s EoS Round-trip signaling message propagation plus emission delay between GA SN16000 and NC SN16000: 0.025s Observations: Setup delays for SONET circuits (OC1, OC3) are small (166ms) Setup delays for Ethernet-over-SONET (EoS) hybrid circuits are much higher (1.6s) (no standard; proprietary implementation) Signaling message processing delays dominate end-to-end circuit setup delays 91 Spectrum of services New services Leased line Verizon BoD escience 10G POTS IP Book-ahead mode Call duration specified Current solution: centralized per-domain path computation/admission control Low call handling volume OSCARS/DRAGON Plain Old Telephone Service (64kbps) Immediate-Request (IR) mode Unspecified call duration Low call setup overhead ( holding times can be shorter) Distributed path computation/admission control High call handling volume CHEETAH 92 46

47 Summary Principles Different types of connection-oriented networks Technologies Single network: MPLS, SONET, OTN Internetworking: PWE3, GFP, G.709 Usage Commercial networks Research & Education Networks (REN) 93 References on bandwidth sharing modes X. Fang and M. Veeraraghavan, On using a hybrid architecture for file transfers, acceptedto IEEE Transactions on Parallel and Distributed Systems, X. Zhu and M. Veeraraghavan, "Analysis and Design of Book-ahead Bandwidth-Sharing Mechanisms," IEEE Transactions on Communications, Dec. 08. X. Fang and M. Veeraraghavan, On using circuit-switched networks for file transfers, in IEEE Globecom, New Orleans, LA, Nov X. Zhu, M. E. McGinley, T. Li, and M. Veeraraghavan, "An Analytical Model for a Book-ahead Bandwidth Scheduler," in IEEE Globecom Washington, DC, Nov X. Zhu, X. Zheng, and M. Veeraraghavan, "Experiences in implementing an experimental wide-area GMPLS network," IEEE Journal on Selected Areas in Communications (JSAC), Apr M. Veeraraghavan, X. Fang, and X. Zheng, On the suitability of applications for GMPLS networks, in IEEE Globecom, San Francisco, CA, Nov

48 References for OTN ITU-T G. 872 and G.709/Y.1331 Specifications T. Walker, Optical Transport Network (OTN) Tutorial, Available online: T/studygroups/com15/otn/OTNtutorial.pdf Agilent, An overview of ITU-T G.709, Application Note 1379 P. Bonenfant and A. Rodriguez-Moral, "Optical Data Networking," IEEE Communications Magazine, Mar. 2000, pp E. L. Varma, S. Sankaranarayanan, G. Newsome, Z.-W. Lin, and H. Esptein, Architecting the Services Optical Network, IEEE Communications Magazine, Sept. 2001, pp References for OSPF-TE RFC Requirements for Traffic Engineering Over MPLS: RFC Traffic Engineering (TE) Extensions to OSPF Version 2: RFC OSPF Extensions in Support of Generalized Multi-Protocol Label Switching (GMPLS) : RFC OSPF Version 2 : OSPFv2 Routing Protocols Extensions for ASON Routing: RFC Routing Extensions in Support of Generalized Multi-Protocol Label Switching (GMPLS): RFC Generalized Multi-Protocol Label Switching (GMPLS) Signaling Functional Description: Dimitri Papadimitriou, IETFInternet Draft, "OSPFv2 Routing Protocols Extensions for ASON Routing," draft-ietf-ccamp-gmpls-ason-routing-ospf- 02.txt, October

49 Reference for GFP/VCAT/LCAS IEEE Communications Magazine, May 2002, Special issue on "Generic Framing Procedure (GFP) and Data over SONET/SDH and OTN," Guest Editors, Tim Armstrong and Steven S. Gorshe 6 excellent papers 97 References for REN projects IEEE Communication Magazine special issue, March 2006 DRAGON, UltraScience Net, CHEETAH, several other projects 98 49