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1
Resource Optimization in Hybrid Core Networks with 100G Links
Malathi VeeraraghavanUniversity of VirginiaDate: Feb. 4, 2010
(Collaborator: Admela Jukan)• Outline
– What is a hybrid network?– Scheduled Dynamic Circuit Service (SDCS)– Single or separate hybrid networks?– SDCS usage– ASCR project software testing on DOE ANI network testbed– Summary
Sponsored by DOE ASCR grant DE-SC0002350
What is a hybrid network?
• A network with – packet switches and circuit switches?– Connection-oriented (CO) and
connectionless (CL) modes of operation?
– All-optical switches and electronic switches?
– “Optical and IP”? [dissimilar items]
2
A classification of switches/gateways
• A circuit switch is necessarily connection-oriented as positions have to be allocated to a communication session before data transfer can start
3
Line cards
(multiplexing)
Controller
(admission
control or not)
Circuit mode(position-based mux:time, frequency, port)
Packet mode
(header-based mux)
Connectionless (CL)(no admission control)
e.g., IP routers, Ethernet switches
Connection-oriented (CO)(admission control)
e.g., SONET, WDM switches
Virtual-circuit switches (VLAN, MPLS)
ESnet: IP-routed network(2006 network)
4
• Is this a hybrid network? – Leased lines between
routers pass through SONET circuit switches
– Thus, packet and circuit switches
– Leased-lines: CO mode
– CO and CL modes– Some switches could
be all-optical (metro rings)
– Thus all-optical and electronic
•Not quite!
From ESnet document dated Oct. 08, 2006
Our understanding of“hybrid network”
• Supports two types of services:– IP-routed service– Dynamic Circuit Service
• To do so, what is required of the network?– Support for connection-oriented (CO) and
connectionless modes– CO mode should support dynamic bandwidth sharing
with control-plane software such as OSCARS schedulers, not just leased-line service
– Circuit or virtual-circuit switches to support the dynamic circuit service
– IP routers– As link speeds and switching capacities increase, all-
optical switches may be required 5
Scheduled Dynamic Circuit Service (SDCS)
• Instead of advance-reservation dynamic circuit service, we propose the name SDCS because– circuit requests can be for immediate usage– so cannot limit it to “advance-reservation” or book-ahead– scheduler (e.g., OSCARS) returns a start time for the
circuit• hence “Scheduled Dynamic Circuit Service”
• Two types of SDCS requests:– User-specified start times (USST): co-scheduling apps
• with instrument or HPC or for a teleconference
– Earliest start time (EST): immediate usage requested, but scheduler returns an assigned start time based on resource availability: suitable for large file transfers
6
How does SDCS fit in with other connectivity services?
7RDP: Rate Duration Product
RDP = 1500B
RDP = 1.4MB (DS0*3 min)
RDP = 5.9TB (T1*1 year)
Gap to fill
How does SDCS differ from leased line service?
8
Leased lineCircuit/VC switch
Customer devicee.g., IP router
Customer devicee.g., cluster computer
SDCS access link SDCS access link
Dynamic circuit
Customer devicee.g., LCD display
Differences
Service Leased line service
Scheduled dynamic circuit service
Components of contract
One contract:• duration• rate• specific endpoints
Two contracts:•SDCS access link of certain rate (like IP access link)•as needed, requests for circuits of certain duration, rate, between any two SDCS endpoints
Duration limit?
No Maximum limit required for acceptable blocking rate/start-time delay with moderate utilization
Call blocking?
No Yes; to achieve moderate utilization, some call blocking should be tolerated
9
• Difficult to articulate differences between a “leased line” and a “dynamic circuit”
• BUT difference between leased-line service and dynamic-circuit service is clear
10
Outline check
• Outline– What is a hybrid network?– Scheduled Dynamic Circuit Service (SDCS) Single or separate hybrid networks?– SDCS usage– ASCR project software testing on DOE ANI network testbed– Summary
Single or separate networks?
• The term “hybrid networking” is more general than “hybrid network”– Hybrid networking: Deploy two
separate networks to support the two services • IP-routed service• Scheduled dynamic circuit service (SDCS)
– Hybrid network: seems to imply a single network
11
ESnet4 (from 2006 talk by Johnston & Burrescia)Core networks 50-60 Gbps by 2009-2010 (10Gb/s circuits),
500-600 Gbps by 2011-2012 (100 Gb/s circuits)
Cle
vela
nd
Europe(GEANT)
Asia-Pacific
New York
Chicago
Washington DC
Atl
anta
CERN (30+ Gbps)
Seattle
Albuquerque
Au
stra
lia
San Diego
LA
Denver
South America(AMPATH)
South America(AMPATH)
Canada(CANARIE)
CERN (30+ Gbps)Canada(CANARIE)
Europe(GEANT)
Asia
-Pac
ific
Asia Pacific
GLORIAD (Russia and
China)
Boise
Houston Jacksonville
Tulsa
Boston
Science Data Network Core
IP Core
Kansa
s City
Au
stra
lia
Core network fiber path is~ 14,000 miles / 24,000 km
1625
mil
es /
2545
km
2700 miles / 4300 km
Sunnyvale
Production IP core (10Gbps)
SDN core (20-30-40-50 Gbps)
MANs (20-60 Gbps) or backbone loops for site access
International connections
IP core hubs
Primary DOE LabsSDN hubs
High speed cross-connectswith Ineternet2/AbilenePossible hubs
USLHCNet
“Single” hybrid network• What does a “single” network mean:
– One node at each PoP– One set of inter-PoP links– One set of customer (e.g., site) access links
• Today’s deployment:– One node at each PoP for ESnet (IP-routed service) and one node
for SDN (dynamic circuit service)– Separate inter-PoP links– Separate site access links– Reasons: Costs of MX vs. M-series interfaces, funding, etc.
• Expenditures saved:– Inter-PoP and site access link costs– Maintenance costs for nodes
• What are the negatives?
13
What is required for a“single” hybrid network
deployment? • Node equipment should support
– IP routing capability– Circuit/VC capability (e.g. VLAN, MPLS,
GMPLS)
• To support IP-routed service and SDCS on a single interface– Circuit/VC based rate enforcement– e.g., VLAN rate policing/limiting
• OSCARS IDC for circuit scheduling
14
Single node supports both IP-forwarding and virtual-circuit capabilities
15
IP (Layer 3)
Ethernet/VLAN (L2)
Access links to sites
and peers
Inter-PoP ESnet links
Leased-linefor IP-routed
service
Dynamic circuit
• Existing equipment already available– Juniper MX series
switches – Cisco 6500 series– Carrier-grade Ethernet
switches
• Separate SDN was proof-of-concept for dynamic circuit service?– Since same type of
node (MX) used in both IP and SDN networks, both services can be offered on one substrate
Part of the ESnet topology (potential single network offering both services)
16
ALBU
DENVPNWG
SUNN
ELPA100 GbE
PNNLIP
Ethernet/VLAN
IP
Ethernet/VLAN
IP
Ethernet/VLAN
IP
Ethernet/VLAN
PE router
PE router
Leased-linefor IP-routed
service
Dynamic circuit
OSCARSIDC
SpectrumNMS
LANL
IP
Ethernet/VLAN
17
Outline check
• Outline– What is a hybrid network?– Scheduled Dynamic Circuit Service (SDCS)– Single or separate hybrid networks? SDCS usage– ASCR project software testing on DOE ANI network testbed– Summary
SDCS deployment
• Successful deployment in the core– important: inter-domain demonstrations– [Scheduled Circuit Routing Protocol: like BGP for
SDCS]
• Status on deployment in:– site networks?
• With site deployments, development of new applications (remote instrument control, WAFS) can be encouraged
• Without data source-to-data sink (end-to-end) reach of SDCS:– usage scenarios for core SDCS service
18
Core network SDCS usage scenarios
• Usage I: Lambdastation– Applications on user hosts (dCache/SRM) communicate
with Lamba Station Server, which runs at the “edge” of sites
– Lambda Station Server communicates with core network IDC to reserve/provision dynamic circuit, and sets PBR in CE router to forward packets corresponding to that particular application flow to the circuit
• Usage II: Automatic long flow detection at PE routers and rerouting to dynamic circuits
• Usage III: Use SDCS instead of leased-line service for creating IP-routed topology, and resize/reroute these router-to-route circuits as aggregate IP loads on these circuits change– Spectrum monitors SNMP data and initiates changes by requesting
these of the IDC 19
Two issues with Usage III• Current ESnet weathermap shows light loading (5%-
20%) on links between IP routers– If SNMP loads indicate a change from 5% to 25%, should
the Spectrum NMS react and increase the rate of the circuit between the two routers?
• Commercial providers note:– Operations divisions typically have strong resistance to
change the network topology because of the potential for:• route flaps, and • drastic changes in the end-end packet latency (e.g., >
10ms)– For these reasons, while theoretically management-plane
traffic and network engineering is a potential user of core SDCS, we expect its use to be limited mainly to failure recovery.
20
Our ASCR project
• Focus on Usage II• Long-flow identification methods:
– 5-tuple rule based flow classification– payload based classification– machine learning algorithms
21
Software implementation and testing on
DOE ANI network testbed
• MFDB: Monitored Flow Data Base• Flows in MFDB mirrored by router to HYNES server• When one of these flows is detected, circuit setup is
initiated and PBR set in router to route flow to circuit 22
Summary
• Proposed name “Scheduled Dynamic Circuit Service (SDCS)” to cover both – advance-reservation – immediate-request
• Hybrid networks support IP-routed service and SDCS
• SDCS: comparison with leased-line service• Single hybrid network deployment• Three usage scenarios for SDCS• HYNES software testing on DOE ANI network
testbed23