connect. communicate. collaborate bandwidth-on-demand system case-study based on gn2 project...

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

Radosław Krzywania (speaker)

PSNC

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

NMS

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

AAI

Resource modelling

Policy module

Inter-domain pathfinder

User interface

Technology Proxy

Domain Manager


User access module


DM pathfinding

AAI

Resource modelling

Policy module


User interface

Client equipment

JRA

3 B

oD s

yste

mD

ata

plan

e

Technology Proxy

Domain Manager


User access module


DM pathfinding

AAI

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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