sdns: hot topics, evolution & research opportunities

SDNs: hot topics, evolution & research opportunities

Diego Kreutz [email protected]

LASIGE - Large-Scale Informatics Systems Laboratory FCUL - Faculty of Sciences of University of Lisbon

2!NavTalks, October, 2012!

Roadmap

1.  HotSDN & HotNets hot topics

2.  SDNs: evolution & improvements

3.  On SDN controllers

4.  Final notes & pointers


Roadmap

1.  HotSDN & HotNets hot topics





HotSDN & HotNets 2012 (hot topics & open research/engineering)

Ø  Troble Shooting and Debugging Ø Delivering assured SDNs §  Make sure they work correctly

Ø  Look more at operators practices Ø  Think more about OpenFlow-like protocols Ø High level abstractions to put intelligence

into the network Ø OpenFlow-based WANs are becoming a

reality


HotSDN & HotNets 2012 (hot topics & open research/engineering)

Ø Seriously engineering (e.g. performance) Ø  Improve SDNs with things from security and

reliability areas Ø Reduce the gap between research and

practical stuff Ø  Think again (“call to arms”)! SDNs are not

yet there. §  We are only on chapter 1. There are at least 9

more chapters to go.


HotSDN & HotNets 2012 (examples of papers/ideas)

Paper: Where is the Debugger for my Software-Defined Network? Ø  Faced problem: debug the network while

developing an in-network load balancer §  Bug 1: no match rule in the middle of the network §  Bug 2: servers at wrong location §  Bug 3: servers that do not connect to clients

Ø Solution: ndb (similar to gdb) §  Allow online debugging §  Use small postcards to reconstruct and debug §  First primitives: breakpoint and backtrace



Paper: Hey, You Darned Counters! Get Off My ASIC! Ø  Faced problem: counters are a big issue in

hardware design and development §  It is not easy and cheap to put specific counters inside

ASICs §  OpenFlow has many counters (per flow/rule: received

packets, received bytes, duration, …) Ø Solution: Software-Defined Counters (SDCs)

§  Use off-the-shelf CPUs §  Let the software/CPUs deal with the counters §  End up with: flexibility, scalability and less hw costs



Paper: Programming Your Network at Run-time for Big Data Applications Ø Problem: waste of networking resources

§  Applications are not optimized for the network §  The network is not optimized for the applications

Ø Solution: NaaS for specific applications (e.g. Hadoop) inside datacenters §  Goal: optimize app performance and net utilization §  Applications can request resources §  Applications can drive the network use §  Routing is done based on each app’s requirements



Paper: Towards Programmable Enterprise WLANs with Odin Ø Problem: association decisions are made by

clients and not the infrastructure §  Handoffs are expensive §  Things such as load distribution are yet not feasible

Ø Solution: light virtual APs (LVAP) with Odin §  Framework do empower network operators

v  No changes on 802.11 standard v  One LVAP abstraction per client (unique BSSID) v  For the app, a user is attached to an “Ethernet port”

§  Applications: seamless mobility, load balancing, … v  Re-association is done by the management software


HotSDN & HotNets 2012 (towards future Internet architectures)

Papers:

Ø  Fabric: A Retrospective on Evolving SDN §  Borrowing ideas from MPLS (simple cores/data planes) §  Separation: fabric and edge elements §  Two OpenFlows? One for edge and one for core/fabric?

Ø  Software-Defined Internet Architecture: Decoupling Architecture from Infrastructure §  Key elements: MPLS, SDNs, Middleboxes, Software Forwarding §  Core routers/backbones: any technology (Fabric-like) §  Edge routers: Software-Defined Routers (SDRs?)

v  Software-based forwarding and control (e.g. OpenFlow)


Roadmap

1.  HotSDN and HotNets hot topics





SDNs: evolution (from LANs to end user NaaS)

1.  LANs: Ethane - Taking Control of the Enterprise 2.  WANs (Wi-Fi): Towards Programmable Enterprise WLANs With Odin 3.  WANs: Inter-Datacenter WAN with centralized TE using SDN and OpenFlow 4.  Backbones: Fabric: A Retrospective on Evolving SDN 5.  Internet architecture: Software-Defined Internet Architecture:

Decoupling Architecture from Infrastructure 6.  Cellular Networks: Toward Software-Defined Cellular Networks

7.  xDSL (and related) Networks: ??? 8.  NaaS (LAN): Programming Your Network at Run-time for Big Data

Applications 9.  NaaS (WAN/LAN): ???


SDNs: evolution

14!NavTalks 2012!

SDNs: evolution (on future NaaS to end users)

MPLS GMPLS

Optical (L1)

SaaS Users

PaaS Users

IaaS Users

SaaS Provider

IaaS Provider

Content Provider

PaaS Provider

Wireless

Broadband

15!NavTalks 2012!

SDNs: improvements (scalability: from 30K to 1M flows/s)

Challenge: 100 edge switches = 10M flows/s Ø  Original NOX: 30K flows/s Ø  Maestro: 300K & 600K flows/s

§  Scales linearly (?) with the number of machines v  10M / 300K = 34 Maestro instances

Ø  NOX-MT: 1M flows/s §  1.8M flows/s for 32/64 edge switches (105 MACs/switch) §  1.0M flows/s for 256 edge switches

v  10M / 1M = 10 NOX-MT instances

Ø  Kandoo: ? flows/s §  Two-layers of controllers (local and root) §  Can easily scale to N (?) on-demand edge switches

16!NavTalks 2012!

SDNs: improvements (scalability: from 30K to 1M flows/s)

Challenge: 100 edge switches = 10M flows/s Ø  Original NOX: 30K flows/s Ø  Maestro: 300K & 600K flows/s

§  Scales linearly (?) with the number of machines v  10M / 300K = 34 Maestro instances

Ø  NOX-MT: 1M flows/s §  1.8M flows/s for 32/64 edge switches (105 MACs/switch) §  1.0M flows/s for 256 edge switches

v  10M / 1M = 10 NOX-MT instances

Ø  Kandoo: ? flows/s §  Two-layers of controllers (local and root) §  Can easily scale to N (?) on-demand edge switches

17!NavTalks 2012!

SDNs: improvements (scalability: fighting with the counters)

Ø DevoFlow §  Reduce control traffic (updates of counters)

Ø Software-Defined Counters (SDCs) §  Solve the counters’ ASIC design problem

Ø DIFANE §  Reduce control overhead (counters)

Ø Software-Defined Cell Networks (SDCNs?) §  Reduce control overhead (counters) §  Use specific TCAMs/tables for DPI

Ø Kandoo §  Scalable controllers (reduce the monitoring overhead)

18!NavTalks 2012!

SDNs: improvements (scalability: fighting with the counters)

Ø DevoFlow §  Reduce control traffic (updates of counters)

Ø Software-Defined Counters (SDCs) §  Solve the counters’ ASIC design problem

Ø DIFANE §  Reduce control overhead (counters)

Ø Software-Defined Cell Networks (SDCNs?) §  Reduce control overhead (counters) §  Use specific TCAMs/tables for DPI

Ø Kandoo §  Scalable controllers (reduce the monitoring overhead)

19!NavTalks 2012!

Roadmap





20!NavTalks 2012!

On SDN controllers (the OpenFlow example)

… … … …

Data plane tier

Controller tier

Application tier

Controller (Server Software) Controller (Server Software)

21!NavTalks 2012!

On SDN controllers (software is now king: take care of it)

… … … …

Controller (Server Software) Controller (Server Software)

Challenge: modular,

updatable and secure software

Challenges: modular, hot-

updatable and secure software

Challenges: modular, hot-updatable, secure and

reliable software

22!NavTalks 2012!

On SDN controllers (inside a controller)

Raw-Packet Task

Queue

Input Stage

Output Stage

Discovery Intradomain

Routing Routing

Table

Authenti-cation

Route Flow

Periodic Timer Discovery

Updates Topology Changes

LLDP Packets

Flow Requests

Flow Requests

Config Msgs

LLDP Packets Triggers

Controller (Server Software)

23!NavTalks 2012!

On SDN controllers (simple app/policies using NOX with FML)

FML (Flow-based Management Language) Basic format: allow(Us, Hs, As, Ut, Ht, At, Prot, Req) <= … Policy P3

allow(Flow) <= Prot = arp allow(Flow) <= Prot = dhcp allow(Flow) <= Ht = auth_server ^ Prot = http

allow(Flow) <= Hs = auth_server ^ Prot = http

Policy P2 httpRedirect(Flow, 307, auth_server) <= Us = unknown ^ Prot = http

Policy P1 deny(Flow) <= Us = unknown

Deny all flows from non-

authenticated users

24!NavTalks 2012!

On SDN controllers

SDN Controller

Interdomain routing Quagga => RouteFlow

25!NavTalks 2012!

On SDN controllers (challenges)

Ø Secure & Resilient Controllers

Ø Examples of open issues §  Distributed controllers (e.g. Onix, HyperFlow)

v  Only weak data consistency v  Only crash faults are tolerated

§  Centralized controllers (e.g. NOX, Foodlight, Beacon, Maestro) v  Single points of failure

§  Common issues (lack of) v  Assured strong data and operation integrity v  Support for tolerating Byzantine behavior

26!NavTalks 2012!

Ø Redundancy §  e.g. controller clusters (e.g. Onix)

Ø Efficient fail-over mechanisms Ø Distribution taking into consideration: §  Strong data consistency mechanisms §  Techniques for strong mutual authentication,

integrity and confidentiality Ø  Fault and Intrusion Tolerant (FIT)

Controllers Ø …

On SDN controllers (things to do/evaluate/improve)

27!NavTalks 2012!

Roadmap





28!NavTalks 2012!

Controllers out there (ready to use tools)

Name Lang Platforms License Link

NOX C++/Python Linux GPL http://www.noxrepo.org/

Floodlight Java Any Apache http://floodlight.openflowhub.org/

Maestro Java Win, Linux, Mac LGPL http://code.google.com/p/maestro-

platform/

Beacon Java Linux, Mac, Win

GPL & FOSS

http://openflow.stanford.edu/display/Beacon

Trema C/Ruby Linux GPL2 http://trema.github.com/trema/

NodeFlow JavaScript http://garyberger.net/?p=537

RouteFlow Linux Apache https://sites.google.com/site/routeflow/

FlowVisor Java https://openflow.stanford.edu/display/DOCS/Flowvisor

See more examples at http://yuba.stanford.edu/~casado/of-sw.html

29!NavTalks 2012!

Ø  Flexibility is the main turn key in SDNs Ø Scalability/performance issues are solvable

§  Ongoing and future engineering & research tasks Ø Software is the king!

§  Going back to software-based forwarding §  Network virtualization is going wild

Ø Keep it simple! Decoupling infra from arch. §  Very simple and efficient data planes (ASICs, …) §  Very simple abstractions (designs & programming) §  Advanced control planes & software apps

Final Notes (try to keep in mind)

30!NavTalks 2012!

Ø ONRC Reseach (Stanford, Berkeley, ON.LAB) §  http://onrc.stanford.edu/research.html

Ø SDNCentral §  http://www.sdncentral.com/

Ø Conferences & Workshops §  Hot-Nets, Hot-SDN, Hot-ICE, … §  SIGCOMM, Usenix NSDI, …

Ø Some tech stuff §  OpenFlow: http://www.openflow.org/ §  OpenvSwitch: http://openvswitch.org/ §  …

Some pointers (cool projects, publications & tech stuff)

sdns: hot topics, evolution & research opportunities

Technology

hotsdn hotnets hot topics

network bug

applications solution

network operators v

softwaredefined network

network use routing

specific applications

examples of papersideas