towards wide-area network virtualization panagiotis papadimitriou leibniz universität hannover with...

Towards Wide-Area Network Virtualization

Panagiotis Papadimitriou

Leibniz Universität Hannover

With acknowledgments to Zdravko Bozakov, David Dietrich, Amr Rizk (Leibniz Universität Hannover)

Laurent Mathy (University of Liege)

Christoph Werle, Roland Bless (Karlsruhe Institute of Technology)

Dagstuhl Seminar on Future Internet

Towards Wide-Area Network VirtualizationDagstuhl Seminar on Future Internet

Introduction

Increasing need for wide-area network service deployment

Network service deployment in the existing Internet infrastructure: Wide-area deployment without any performance or reliability guarantees Performance and reliability for services deployed at an ISP

Deployment limited to the ISP’s geographic footprint

How can we enable the coexistence of multiple service-tailored networks at large scale?

2


Network Virtualization: An Enabler

3

Management of Virtual Networks

Provisioning of Virtual Networks(on-demand instantiation of virtual networks)

PhysicalInfrastructure

VirtualizedSubstrate

VirtualNetwork

VirtualNetwork

Virtualization of Resources(partitioning of physical infrastructure into “slices”)

Management of Virtual Networks

Provisioning of Virtual Networks(on-demand instantiation of virtual networks)

PhysicalInfrastructure

VirtualizedSubstrate

VirtualNetwork

VirtualNetwork

Virtualization of Resources(partitioning of physical infrastructure into “slices”)


Roles and Actors

4

Service Provider

Service Provider (SP) Deploys services on VNs

Infrastructure Provider (InP) Owns and manages the physical

infrastructure Leases resources for VNs


VN Request

Roles and Actors

5




Service Provider


Roles and Actors

6

Service Provider

?




VN Request


Roles and Actors

7

Service Provider


Virtual Network Provider (VNP) Assembles resources from one or

multiple InPs into a VN



VN Provider

VN Request


Challenges

8

Service Provider

VN Provider

Limited knowledge of the substrate network: Substrate network topology Substrate resource availability

Interoperability between InPs: Inter-domain virtual link setup

VN Request


Substrate Network Visibility

9

?

?? VN Provider‘s visibility on substrate

network topology and resources is limited to:



10

VN Provider‘s visibility on substrate network topology and resources is limited to:

Offered virtual node types (similar to Amazon EC2)



11



Location of peering nodes



12



Location of peering nodes

Cost for sending traffic between peering nodes


VN Request Description

VN topology (undirected weighted graph) as VN request description:

Introduces constraints in VN embedding

SPs may prefer a higher level of abstraction

Alternative VN request descriptions:

Bandwidth demands expressed by a traffic matrix

Hose model

13


Multi-Domain Virtual Network Embedding

14



Resource Assignment

Resource Matching

VN Request

VN Setup

15

VN Request Partitioning

Resource Allocation

InP

VN Provider



Resource Assignment

Resource Matching

VN Request

VN Setup

16


Resource Allocation

InP

VN Provider


Resource Matching

17

VN Provider matches requested to advertised resources Candidates for each requested

resource are identified


Resource Matching

18




Resource Matching

19




Resource Matching

20




Resource Matching

21





22

VN Provider partitions the VN request among InPs

Objective: Minimize the expenditure for the Service Provider

Output: VN segment requests (virtual nodes assigned to peering nodes, bandwidth demands)



23






24





Resource Assignment

25

Each InP maps its assigned VN segment onto its substrate network:

VN segment mapping should comply with the virtual node to peering node bindings


VN Embedding Efficiency with LID

Comparison method:

Limited information disclosure (LID) vs. full information disclosure (FID)

VN embedding cost

VN request acceptance rate

26


Extra Cost under LID

27

LID incurs15-30% extra cost


Origins of Extra Cost

28

Extra cost is correlated with extra link cost Extra link cost is due to longer paths


VN Request Acceptance Rate

29

Lower VN acceptance rate and revenue for InPs under LID


Virtual Link Setup

30


Virtual Link Setup

Objective: Interoperable solution for virtual link setup with QoS guarantees across

InPs

Approach: Couple virtual link setup signaling with QoS reservation signaling for

efficiency Rely on existing QoS resource reservation protocol (IETF NSIS) Add new object to NSIS QoS NSLP to carry the required information

for virtual link setup

Requirements: NSIS support in routers IP-based substrate New QoS NSLP object support (only) in virtual link end-points


Virtual Link Setup Protocol (VLSP)

NSIS QoS NSLP extension with new Virtual Link Setup Protocol (VLSP) object: Virtual link setup at the end-points via VLSP Resource reservation and QoS via NSLP object at the intermediate nodes

Virtual Network ID

Source Virtual Node ID

Destination Virtual Node ID

Source Virtual Interface ID Destination Virtual Interface ID

Virtual Link ID (optional) Virtual Link Type (optional)

640 127

GIST

TCP/UDP/…

QoSNSLP

VLSP

IP

NTLP

NSLP

VLSP object NSIS QoS NSLP/VLSP


Virtual Link Setup Workflow

NSISDaemon

Router X

eth0

IP forwarding

eth0

ManagementDaemon

NSISDaemon

VM2VM1

InPManagement

Node

Router A Router B

eth0

vif1

VM2

Multiplexing/QoS Multiplexing/QoS

eth1IP in IP tunnel

VM1

vif1

ManagementDaemon

NSISDaemon



NSISDaemon

Router X

eth0

IP forwarding

eth0

ManagementDaemon

NSISDaemon

VM2VM1

InPManagement

Node

Router A Router B

eth0

vif1

VM2


1. Setup virtual link from VM1@A VM1@B

eth1IP in IP tunnel

VM1

vif1

ManagementDaemon

NSISDaemon



NSISDaemon

Router X

eth0

IP forwarding

eth0

ManagementDaemon

NSISDaemon

VM2VM1

InPManagement

Node

Router A Router B

eth0

vif1

VM2



2. Initialize virtual link setupVM1@A VM1@B

eth1IP in IP tunnel

VM1

vif1

ManagementDaemon

NSISDaemon



NSISDaemon

Router X

eth0

IP forwarding

eth0

ManagementDaemon

NSISDaemon

VM2VM1

InPManagement

Node

Router A Router B

eth0

vif1

VM2



3. RESERVE+ VLSP Object


eth1IP in IP tunnel

VM1

vif1

ManagementDaemon

NSISDaemon



NSISDaemon

Router X

eth0

IP forwarding

eth0

ManagementDaemon

NSISDaemon

VM2VM1

InPManagement

Node

Router A Router B

eth0

vif1

VM2




4. Ignore VLSP object, perform admission control


eth1IP in IP tunnel

VM1

vif1

ManagementDaemon

NSISDaemon



NSISDaemon

Router X

eth0

IP forwarding

eth0

ManagementDaemon

NSISDaemon

VM2VM1

InPManagement

Node

Router A Router B

eth0

vif1

VM2







eth1IP in IP tunnel

VM1

vif1

ManagementDaemon

NSISDaemon



NSISDaemon

Router X

eth0

IP forwarding

eth0

ManagementDaemon

NSISDaemon

VM2VM1

InPManagement

Node

Router A Router B

eth0

vif1

VM2







6. Setup virtual linkVM1@A VM1@B

eth1IP in IP tunnel

VM1

vif1

ManagementDaemon

NSISDaemon



NSISDaemon

Router X

eth0

IP forwarding

eth0

ManagementDaemon

NSISDaemon

VM2VM1

InPManagement

Node

Router A Router B

eth0

vif1

VM2







7. RESPONSE


eth1IP in IP tunnel

VM1

vif1

ManagementDaemon

NSISDaemon



NSISDaemon

Router X

eth0

IP forwarding

eth0

ManagementDaemon

NSISDaemon

VM2VM1

InPManagement

Node

Router A Router B

eth0

vif1

VM2







7. RESPONSE


eth1

8. Reserve resources

IP in IP tunnel

VM1

vif1

ManagementDaemon

NSISDaemon



NSISDaemon

Router X

eth0

IP forwarding

eth0

ManagementDaemon

NSISDaemon

VM2VM1

InPManagement

Node

Router A Router B

eth0

vif1

VM2







7. RESPONSE

9. RESPONSE


eth1


IP in IP tunnel

VM1

vif1

ManagementDaemon

NSISDaemon



NSISDaemon

Router X

eth0

IP forwarding

eth0

ManagementDaemon

NSISDaemon

VM2VM1

InPManagement

Node

Router A Router B

eth0

vif1

VM2







7. RESPONSE

9. RESPONSE


eth1



virtual link

IP in IP tunnel

VM1

vif1

ManagementDaemon

NSISDaemon


SDN Virtualization

44


SDN Virtualization

Tenants are granted virtual networks with limited control and access on network devices

45


SDN Virtualization

Tenants are granted virtual networks with limited control and access on network devices

Solution: Virtual networks programmable as SDNs (vSDNs)

SDN virtualization benefits:

Tenants: Advanced control and access on network slices

Providers: New cloud computing model:

SDN as a Service (SDNaaS)

46


SDN Virtualization Challenges

Automation of vSDN setup vSDN mapping Transparent allocation of isolated flowspaces

Selection of identifiers Generation and installation of flow entries for packet forwarding and

encapsulation Binding traffic to logical context using tagging

Transparent vSDN operation Translation of references to logical/physical resource identifiers to

appropriate context Policy control to prevent access to unauthorized vSDN resources

Scalability of hypervisor Distribution of vSDN configurations across multiple controllers

47


SDN Hypervisor Overview

Distributed hypervisor Multiple autonomous controller

proxies Coordinated by management

module

Dataplane segmentation Multiple SDN domains Switches within a domain controlled

by the same controller proxy

48


SDN Hypervisor Design Challenges

Collaboration among controller proxies for operations across multiple SDN domains

Dynamic segmentation of SDN as vSDNs are provisioned or released

Support for arbitrary vSDN topologies

Suitability of existing virtual network embedding algorithms for vSDN mapping

49


Conclusions

Multi-domain VN embedding with VNPs: Suboptimality due to limited information disclosure

One example of emerging business models that require separation between the network operations and the physical infrastructure

Will VNPs materialize or a single InP will prevail (Amazon)?

New cloud computing models may emerge from SDN virtualization Scalable SDN hypervisor design entails significant challenges

50

Towards Wide-Area Network VirtualizationDagstuhl Seminar on Future Internet 51

Thank you!Panagiotis Papadimitriou

E-mail: [email protected]

WWW: http://www.ikt.uni-hannover.de/

towards wide-area network virtualization panagiotis papadimitriou leibniz universität hannover with...

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