Connect. Communicate. Collaborate BANDWIDTH-ON-DEMAND SYSTEM CASE-STUDY BASED ON GN2 PROJECT...

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Connect. Communicate. Collaborate

BANDWIDTH-ON-DEMAND SYSTEM CASE-STUDY BASED ON GN2 PROJECT EXPERIENCES

Radosław Krzywania (speaker)

Mauro CampanellaGARR

Afrodite SevastiGRNET

Connect. Communicate. CollaborateAgenda

• Introduction• Technology Choice• Domain Privacy• Pathfinding• Advance Reservations

Connect. Communicate. CollaborateJRA3 AutoBAHN – Geant2

• AutoBAHN = Automated Bandwidth Allocation across Heterogeneous Networks

• A ‘Joint Research Activity’ investigating the provision of ‘Bandwidth on Demand’ services to the NREN community

• The environment:– Multi-domain– Multiple technologies– Requirements for:

• end-to-end non-contended capacity • a standardized interface for service requests at end-points• service level indication to end-users• advance reservation (scheduled)

Connect. Communicate. CollaborateArchitecture overview

Client equipment

IP domain

GE domain

L2 MPLS VPN

SDH domain

Native EthernetGFP over SDH

GMPLS signalling

Technology Proxy

Domain Manager

Inter-Domain Manager

User access module

Request handling logic

DM pathfinding

Resource modelling

Policy module

Inter-domain pathfinder

User interface

Technology Proxy

Domain Manager

User access module

DM pathfinding

Resource modelling

Policy module

User interface

Client equipment

Technology Proxy

Domain Manager

User access module

DM pathfinding

Resource modelling

Policy module

User interface

Connect. Communicate. CollaborateTechnology Choice

• European network is heterogeneous

• Each NREN develops its own architecture independently, relying on various technology

• NRENs are interconnected through GEANT2 pan-European network

• NRENs can connect with each other with cross-border links, evading GEANT2 infrastructure

Connect. Communicate. CollaborateTechnology Choice

• AutoBAHN aims at the following technologies:– Layer 1

• lambda circuit management– Layer 2

• MPLS VPNs• Gb Ethernet• SDH• GFP over SDH

• Layer 3 technologies are out of scope, as they belong to the responsibility of other GEANT2 activities.

Connect. Communicate. Collaborate

• Domain Privacy– AutoBAHN aims at operating

over a federated architecture, where each domain is independent

– The AAI and domain privacy is a key issue

– Each domain would like to hide its internal details from other domains

– The public advertisements are limited to reachablity information only

Connect. Communicate. CollaborateDomain Privacy

• Various representations of abstracted domains– 1 to 1 representation– Aggregated nodes– Edge nodes only (currently

used by AutoBAHN)– Single node

Connect. Communicate. CollaborateDomain Privacy

• Aggregation of attributes issue– If alternative paths will be

abstracted to single one, what attribute values should be used?

– It is impossible to have a 10Gbps path with 10ms delay and cost of 15 points…

Connect. Communicate. CollaboratePathfinding

• Single point computation – Detailed

– The advertised domain topologies include information about internal nodes and attributes (limited domain privacy, peering model)

– The path contains exact nodes and links in each domain along the reservation path between two end points

– The path is computed in one domain (any domain manager, PCE, etc.)

Connect. Communicate. CollaboratePathfinding• Single point computation – General

– The advertised domain topologies are abstracted, no (or limited) intra-domain details are visible

– The path contains only domains that should be traversed by a path (ingress and egress domain points)

– Each domain must perform local pathfinding to find a detailed part of inter-domain path (this part may be published or hidden due privacy reasons)

– The inter-domain path is computed in single point, the domain details must be computed in each domain

• Distributed computation– Inter-domain topologies

provide only routing information

– Instead of defining a full path, each domain defines only the „next hop domain”

– Each domain defines its part of the path in detail, including outgoing inter-domain links

• AutoBAHN inter-domain pathfinding is performed based on inter-domain abstracted topology (reachability information between domains + abstracted intra-domain links), which is built with OSPF Quagga daemon.

• Currently Dijkstra algorithm is used to find a potential inter-domain path.

• The information on abstracted topology database are insufficient to perform a reservation, therefore an additional process (negotiation) is required to validate the path.

• During the process each domain is queried for details and validation of inter-domain part of the path. The details are called constraints

• The last domain on a path is responsible to agree all constraints and prepare a final set of reservation attributes, which includes technology specific parameters.

• Introduction • Technology Choice• Domain Privacy• Pathfinding• Advance Reservations

Connect. Communicate. CollaborateAdvance Reservations

• AutoBAHN allows to perform advance reservations– Each reservation has start and end time attributes

attached– Resources are booked, not configured – a calendar

module is used– At reservation time, involved domains configure the

network to build a circuit– When reservation time expires, domain removes circuit

configuration

• Inter-domain centralized approach– Calendar must be aware of

each particular resource in every domain (limited domain privacy)

– One place of data storage (simple maintenance)

– Easy to implement

• Inter-domain distributed approach– Each domain has its own

calendar– Domain privacy may be kept– Synchronization of

databases is required (for inter-domain resources)

– More complex solution than centralized approach

• Intra-domain centralized approach– There is one calendar

instance per domain– The calendar is aware of

each resource under control of BoD system

– Easy to implement and maintain

– Single point of data storage

• Intra-domain distributed approach– Each resource or resource

group has it’s own calendar module

– The synchronization is required between calendars for shared resources (e.g. links)

– Interaction with external domains is more complex than in centralized approach

– Calendars should be part of equipment – vendor support

• Pathfinding– Pathfinder (PF) module is

request to find a chain of domains, which should be involved in circuit creation

– Pathfinder takes a snapshot of current abstract topology view (includes other domain information as advertised by Quagga)

– Dijkstra algorithm is executed to find best paths (delay value is used as optimization attribute)

• Negotiations– All domains (included in

circuit) are involved in negotiation process

– Each domain checks possible intra-domain paths and validates resource availability for reservation time

– The constraint entities are created, which describe domain requirements for particular reservation (e.g. allowed VLAN range or SDH time slots)

• Negotiations– The constraints are collected

from all domains along reservation path

– The destination domain is responsible to concatenate all constraints in order to find common set of configuration attributes

– If such set is found, the resources are booked in all domains’ calendars along the way back to source domain

• Reservation– Each domain is responsible

for initialization of circuit configuration, when reservation time starts (calendar module)

– DM configures circuit through Technology Proxy module

– Source domain IDM module is notified about circuit creation in all domains

– Similar proces is executed to remove circuit configuration

Connect. Communicate. CollaborateJRA3 AutoBAHN Partners

• The JRA3 work is a joint effort of the following NRENs & DANTE– CARNET– CESNET– DANTE– FCCN– GARR– GRNET– HEANET– HUNGARNET– PSNC– REDIRIS– RENATER– SURFNET

• This presentation was co-authored by– Mauro Campanella (GARR) – Afrodite Sevasti (GRNET)

Connect. Communicate. CollaborateQ&A

• Thank you for your attention

Connect. Communicate. Collaborate BANDWIDTH-ON-DEMAND SYSTEM CASE-STUDY BASED ON GN2 PROJECT...

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