16 September The ongoing evolution from Packet based networks to Hybrid Networks in Research & Education Networks Olivier Martin, CERN NEC’2005 Conference, VARNA (Bulgaria)

16 September 2005 NEC’2005 conference Slide 2 Presentation Outline The demise of conventional packet based networks in the R&E community The advent of community managed dark fiber networks The Grid & its associated Wide Area Networking challenges « on-demand Lambda Grids » Ethernet over SONET & new standards –WAN-PHY, GFP, VCAT/LCAS, G.709, OTN

Olivier H. Martin (3)

16 September 2005 NEC’2005 conference Slide 4 System Capacity (Mbit/s) Year Optical DWDM Capacity Ethernet Internet Backbone T1 T3 OC-3c OC-12c OC-48c 10-GE Ethernet Fast Ethernet GigE OC-192c 135 Mbit/s 565 Mbit/s 1.7 Gbit/s OC-48c 10 Gbit/s Gbit/s 160   10 Gbit/s 32  10 Gbit/s 16  10 Gbit/s 8 10 Gbit/s 4 10 Gbit/s 2 I/0 Rates = Optical Wavelength Capacity OC-768c 40-GE

Olivier H. Martin (5) Internet Backbone Speeds T1 Lines T3 lines OC3c OC12c IP/ ATM-VCs MBPS

Olivier H. Martin (6) Higher Speed, Lower cost, complexity and overhead High Speed IP Network Transport Trends B-ISDN IP Over SONET/SDH IP SONET/SDH Optical ATM SONET/SDH IP Optical IP Over Optical IP Optical IP Over ATM ATM SONET/SDH IP Optical Multiplexing, protection and management at every layer Signalling

Olivier H. Martin (7)

Olivier H. Martin (8)

Olivier H. Martin (9)

October 12, 2001Intro to Grid Computing and Globus Toolkit™10 Network Exponentials l Network vs. computer performance –Computer speed doubles every 18 months –Network speed doubles every 9 months –Difference = order of magnitude per 5 years l 1986 to 2000 –Computers: x 500 –Networks: x 340,000 l 2001 to 2010 –Computers: x 60 –Networks: x 4000 Moore’s Law vs. storage improvements vs. optical improvements. Graph from Scientific American (Jan- 2001) by Cleo Vilett, source Vined Khoslan, Kleiner, Caufield and Perkins.

Know the user BW requirements # of users C A B A -> Lightweight users, browsing, mailing, home use B -> Business applications, multicast, streaming, VPN’s, mostly LAN C -> Special scientific applications, computing, data grids, virtual-presence ADSLGigE LAN (3 of 12) F(t)

What the user BW requirements Total BW C A B A -> Need full Internet routing, one to many B -> Need VPN services on/and full Internet routing, several to several C -> Need very fat pipes, limited multiple Virtual Organizations, few to few ADSLGigE LAN (4 of 12)

So what are the facts Costs of fat pipes (fibers) are one/third of equipment to light them up –Is what Lambda salesmen told Cees de Laat (University of Amsterdam & Surfnet) Costs of optical equipment 10% of switching 10 % of full routing equipment for same throughput –100 Byte 10 Gb/s -> 80 ns to look up in 100 Mbyte routing table (light speed from me to you on the back row!) Big sciences need fat pipes Bottom line: create a hybrid architecture which serves all users in one coherent and cost effective way (5 of 12)

Utilization trends Gbps Network Capacity Limit Jan 2005

Today’s hierarchical IP network University Region al National or Pan-National IP Network Other national networks NREN A NREN B NREN C NREN D

Tomorrow’s peer to peer IP network World University Region al Server World National DWDM Network NREN A NREN B NREN C NREN D Child Lightpaths Child Lightpaths

Creation of application VPNs Commodity Internet Bio-informatics Network University CERN University High Energy Physics Network eVLBI Network Dept Research Network Direct connect bypasses campus firewall

Production vs Research Campus Networks >Increasingly campuses are deploying parallel networks for high end users >Reduces costs by providing high end network capability to only those who need it >Limitations of campus firewall and border router are eliminated >Many issues in regards to security, back door routing, etc >Campus networks may follow same evolution as campus computing >Discipline specific networks being extended into the campus

UCLP intended for projects like National LambdaRail CAVEwave acquires a separate wavelength between Seattle and Chicago and wants to manage it as part of its network including add/drop, routing, partition etc NLR Condominium lambda network Original CAVEwave

GEANT2 POP Design

UltraLight Optical Exchange Point u L1, L2 and L3 services u Interfaces  1GE and 10GE  10GE WAN-PHY (SONET friendly) u Hybrid packet- and circuit-switched PoP  Interface between packet- & circuit-switched networks u Control plane is L3 Photonic switch Calient or Glimmerglass Photonic Cross Connect Switch

16 September 2005 NEC’2005 conference Slide 22 LHC Data Grid Hierarchy Tier 1 Tier2 Center Online System CERN 700k SI95 ~1 PB Disk; Tape Robot FNAL: 200k SI95; 600 TB IN2P3 Center INFN Center RAL Center Institute Institute ~0.25TIPS Workstations ~ MBytes/sec 2.5/10 Gbps 0.1–1 Gbps Physicists work on analysis “channels” Each institute has ~10 physicists working on one or more channels Physics data cache ~PByte/sec 10 Gbps Tier2 Center ~2.5 Gbps Tier 0 +1 Tier 3 Tier 4 Tier2 Center Tier 2 Experiment CERN/Outside Resource Ratio ~1:2 Tier0/(  Tier1)/(  Tier2) ~1:1:1

16 September 2005 NEC’2005 conference Slide 23 grid for a physics study group Deploying the LHC Grid grid for a regional group Tier2 Lab a Uni a Lab c Uni n Lab m Lab b Uni b Uni y Uni x Tier3 physics department    Desktop Germany Tier 1 USA UK France Italy Taipei? CERN Tier 1 Japan The LHC Computing Centre CERN Tier 0

16 September 2005 NEC’2005 conference Slide 24 What you get Tier2 Lab a Uni a Lab c Uni n Lab m Lab b Uni b Uni y Uni x physics department    physicist Germany Tier 1 USA UK France Italy ………. CERN Tier 1 Japan CERN Tier 0

16 September 2005 NEC’2005 conference Slide 25 Main Networking Challenges Fulfill the, yet unproven, assertion that the network can be « nearly » transparent to the Grid Deploy suitable Wide Area Network infrastructure ( Gb/s) Deploy suitable Local Area Network infrastructure (matching or exceeding that of the WAN) Seamless interconnection of LAN & WAN infrastructures firewall? End to End issues (transport protocols, PCs (Itanium, Xeon), 10GigE NICs (Intel, S2io), where are we today:  memory to memory: 7.5Gb/s (PCI bus limit)  memory to disk: 1.2MB (Windows 2003 server/NewiSys)  disk to disk: 400MB (Linux), 600MB (Windows)

16 September 2005 NEC’2005 conference Slide 26 Main TCP issues Does not scale to some environments  High speed, high latency  Noisy Unfair behaviour with respect to:  Round Trip Time (RTT  Frame size (MSS)  Access Bandwidth Widespread use of multiple streams in order to compensate for inherent TCP/IP limitations (e.g. Gridftp, BBftp):  Bandage rather than a cure New TCP/IP proposals in order to restore performance in single stream environments  Not clear if/when it will have a real impact  In the mean time there is an absolute requirement for backbones with: – Zero packet losses, – And no packet re-ordering  Which re-inforces the case for “lambda Grids”

16 September 2005 NEC’2005 conference Slide 27 TCP dynamics (10Gbps, 100ms RTT, 1500Bytes packets) Window size (W) = Bandwidth*Round Trip Time –Wbits = 10Gbps*100ms = 1Gb –Wpackets = 1Gb/(8*1500) = packets Standard Additive Increase Multiplicative Decrease (AIMD) mechanisms: –W=W/2 (halving the congestion window on loss event) –W=W + 1 (increasing congestion window by one packet every RTT) Time to recover from W/2 to W (congestion avoidance) at 1 packet per RTT: –RTT*Wp/2 = hour –In practice, 1 packet per 2 RTT because of delayed acks, i.e hour Packets per second: –RTT*Wpackets = 833’333 packets

Single TCP stream performance under periodic losses Loss rate =0.01%: è LAN BW utilization= 99% è WAN BW utilization=1.2% Bandwidth available = 1 Gbps  TCP throughput much more sensitive to packet loss in WANs than LANs  TCP’s congestion control algorithm (AIMD) is not well-suited to gigabit networks  The effect of packets loss can be disastrous  TCP is inefficient in high bandwidth*delay networks  The future performance-outlook for computational grids looks bad if we continue to rely solely on the widely-deployed TCP RENO

ResponsivenessPathBandwidth RTT (ms) MTU (Byte) Time to recover LAN 10 Gb/s ms Geneva–Chicago 10 Gb/s hr 32 min Geneva-Los Angeles 1 Gb/s min Geneva-Los Angeles 10 Gb/s hr 51 min Geneva-Los Angeles 10 Gb/s min Geneva-Los Angeles 10 Gb/s k (TSO) 5 min Geneva-Tokyo 1 Gb/s hr 04 min  Large MTU accelerates the growth of the window  Time to recover from a packet loss decreases with large MTU  Larger MTU reduces overhead per frames (saves CPU cycles, reduces the number of packets)  C. RTT 2. MSS 2 C : Capacity of the link  Time to recover from a single packet loss:

16 September 2005 NEC’2005 conference Slide 30 Internet2 land speed record history (IPv4 & IPv6) period

16 September 2005 NEC’2005 conference Slide 31 Layer1/2/3 networking (1) Conventional layer 3 technology is no longer fashionable because of: –High associated costs, e.g. 200/300 KUSD for a 10G router interfaces –Implied use of shared backbones The use of layer 1 or layer 2 technology is very attractive because it helps to solve a number of problems, e.g. –1500 bytes Ethernet frame size (layer1) –Protocol transparency (layer1 & layer2) –Minimum functionality hence, in theory, much lower costs (layer1&2)

16 September 2005 NEC’2005 conference Slide 32 Layer1/2/3 networking (2) « 0n-demand Lambda Grids » are becoming very popular: Pros: circuit oriented model like the telephone network, hence no need for complex transport protocols Lower equipment costs (i.e. « in theory » a factor 2 or 3 per layer) the concept of a dedicated end to end light path is very elegant Cons: « End to end » still very loosely defined, i.e. site to site, cluster to cluster or really host to host Higher circuit costs, Scalability, Additional middleware to deal with circuit set up/tear down, etc Extending dynamic VLAN functionality is a potential nightmare!

16 September 2005 NEC’2005 conference Slide 33 « Lambda Grids » What does it mean? Clearly different things to different people, hence the apparently easy consensus! Conservatively, on demand « site to site » connectivity  Where is the innovation?  What does it solve in terms of transport protocols?  Where are the savings? Less interfaces needed (customer) but more standby/idle circuits needed (provider) Economics from the service provider vs the customer perspective? –Traditionally, switched services have been very expensive, »Usage vs flat charge »Break even, switches vs leased, few hours/day »Why would this change? In case there are no savings, why bother? More advanced, cluster to cluster  Implies even more active circuits in paralle  Is it realistic? Even more advanced, Host to Host or even « per flow »  All optical  Is it really realisitic?

16 September 2005 NEC’2005 conference Slide 34 Some Challenges Real bandwidth estimates given the chaotic nature of the requirements. End-end performance given the whole chain involved –(disk-bus-memory-bus-network-bus-memory-bus- disk) Provisioning over complex network infrastructures (GEANT, NREN’s etc) Cost model for options (packet+SLA’s, circuit switched etc) Consistent Performance (dealing with firewalls) Merging leading edge research with production networking

16 September 2005 NEC’2005 conference Slide 35 Tentative conclusions  There is a very clear trend towards community managed dark fiber networks  As a consequence National Research & Education Networks are evolving into Telecom Operators, is it right?  In the short term, almost certainly YES  In the longer term, probably NO In many countries, there is NO other way to have affordable access to multi-Gbit/s networks, therefore this is clearly the right move The Grid & its associated Wide Area Networking challenges « on-demand Lambda Grids » are, according to me, extremely doubtful! Ethernet over SONET & new standards will revolutionize the Internet  WAN-PHY (IEEE) has, according to me NO future!  However, GFP, VCAT/LCAS, G.709, OTN are very likely to have a very bright future.

Single TCP stream between Caltech and CERN u Available (PCI-X) Bandwidth=8.5 Gbps u RTT=250ms (16’000 km) u 9000 Byte MTU u 15 min to increase throughput from 3 to 6 Gbps u Sending station:  Tyan S2882 motherboard, 2x Opteron 2.4 GHz, 2 GB DDR. u Receiving station:  CERN OpenLab:HP rx4640, 4x 1.5GHz Itanium-2, zx1 chipset, 8GB memory u Network adapter:  S2IO 10 GbE Burst of packet losses Single packet loss CPU load = 100%

High Throughput Disk to Disk Transfers: From 0.1 to 1GByte/sec  Server Hardware (Rather than Network) Bottlenecks:  Write/read and transmit tasks share the same limited resources: CPU, PCI-X bus, memory, IO chipset  PCI-X bus bandwidth: 8.5 Gbps [133MHz x 64 bit]  Link aggregation (802.3ad): Logical interface with two physical interfaces on two independent PCI-X buses.  LAN test: 11.1 Gbps (memory to memory) Performance in this range (from 100 MByte/sec up to 1 GByte/sec) is required to build a responsive Grid-based Processing and Analysis System for LHC

Transferring a TB from Caltech to CERN in 64-bit MS Windows  Latest disk to disk over 10Gbps WAN: 4.3 Gbits/sec (536 MB/sec) - 8 TCP streams from CERN to Caltech; 1TB file  3 Supermicro Marvell SATA disk controllers + 24 SATA 7200rpm SATA disks  Local Disk IO – 9.6 Gbits/sec (1.2 GBytes/sec read/write, with <20% CPU utilization)  S2io SR 10GE NIC  10 GE NIC – 7.5 Gbits/sec (memory-to-memory, with 52% CPU utilization)  2*10 GE NIC (802.3ad link aggregation) – 11.1 Gbits/sec (memory-to-memory)  Memory to Memory WAN data flow, and local Memory to Disk read/write flow, are not matched when combining the two operations  Quad Opteron AMD GHz processors with 3 AMD-8131 chipsets: 4 64-bit/133MHz PCI-X slots.  Interrupt Affinity Filter: allows a user to change the CPU-affinity of the interrupts in a system.  Overcome packet loss with re-connect logic.  Proposed Internet2 Terabyte File Transfer Benchmark

UltraLight: Developing Advanced Network Services for Data Intensive HEP Applications  UltraLight: a next-generation hybrid packet- and circuit- switched network infrastructure  Packet switched: cost effective solution; requires ultrascale protocols to share 10G efficiently and fairly  Circuit-switched: Scheduled or sudden “overflow” demands handled by provisioning additional wavelengths; Use path diversity, e.g. across the US, Atlantic, Canada,…  Extend and augment existing grid computing infrastructures (currently focused on CPU/storage) to include the network as an integral component  Using MonALISA to monitor and manage global systems  Partners: Caltech, UF, FIU, UMich, SLAC, FNAL, MIT/Haystack; CERN, NLR, CENIC, Internet2; Translight, UKLight, Netherlight; UvA, UCL, KEK, Taiwan  Strong support from Cisco

UltraLight MPLS Network u Compute path from one given node to another such that the path does not violate any constraints (bandwidth/administrative requirements) u Ability to set the path the traffic will take through the network (with simple configuration, management, and provisioning mechanisms)  Take advantage of the multiplicity of waves/L2 channels across the US (NLR, HOPI, Ultranet and Abilene/ESnet MPLS services) u EoMPLS will be used to build layer2 paths u natural step toward the deployment of GMPLS

Summary  For many years the Wide Area Network has been the bottleneck; this is no longer the case in many countries thus making deployment of a data intensive Grid infrastructure possible!  Recent I2LSR records show for the first time ever that the network can be truly transparent and that throughputs are limited by the end hosts  Challenge shifted from getting adequate bandwidth to deploying adequate infrastructure to make effective use of it!  Some transport protocol issues still need to be resolved; however there are many encouraging signs that practical solutions may now be in sight.  1GByte/sec disk to disk challenge. Today: 1 TB at 536 MB/sec from CERN to Caltech  Still in Early Stages; Expect Substantial Improvements  Next generation network and Grid system: UltraLight  Deliver the critical missing component for future eScience: the integrated, managed network  Extend and augment existing grid computing infrastructures (currently focused on CPU/storage) to include the network as an integral component.

16 September 2005 NEC’2005 conference Slide 42 10G DataTAG testbed extension to Telecom World 2003 and Abilene/Cenic On September 15, 2003, the DataTAG project was the first transatlantic testbed offering direct 10GigE access using Juniper’s VPN layer2/10GigE emulation.