- 1. v The House That CLOS Built Network Architecture For the
Modern Data Center Dinesh Dutt, Chief Scientist 20th August,
2014
2. Cumulus Networks: Making Networks Accessible Mission To
enable high capacity networks that are easy to deploy and
affordable helping customers realize the full promise of the
software-defined data center. Vision Bringing the Linux Revolution
to Networking 3. cumulusnetworks.com 3 The Rise of the Modern Data
Center Networks 2.0: The New World Agenda 4. cumulusnetworks.com 4
The Rise of the Modern Data Center Networks 2.0: The New World
Agenda 5. The Winds Of Change Are Blowing Through Networking
cumulusnetworks.com 5 Image credit:
http://anciss.deviantart.com/art/you-can-change-the-world-81681894
SDN Bare Metal Switching DevOps Commoditization of Networking
Network Virtualization 6. A Key Transformation cumulusnetworks.com
6 SPINE LEAF CORE L2 ACCESS L3 AGGREGATION 7. What Changed ? A new
generation of applications: Search Big Data Clouds Other Web 2.0
Applications cumulusnetworks.com 7 8. Characteristics of the New
Applications Traffic Pattern Between servers (East-West) instead of
client-server (North-South) Scale 10s of thousands to 100s of
thousands of endpoints Agility New endpoints and racks powered up
in hours instead of weeks New networks spun up in seconds instead
of weeks Flexibility Ability to reuse same infrastructure for
different applications Resilience Fine grained failure domain
cumulusnetworks.com 8 9. Where The Existing Topology Falls Short
cumulusnetworks.com 9 Not suited for E-W traffic Heavy-core, lean
edge design is not scalable Not Agile Inflexible Design
Coarse-grained failure domain Unpredictable Latency CORE L2 ACCESS
L3 AGGREGATION 10. The Case Against Complexity cumulusnetworks.com
10 Too many protocols Many proprietary (MLAG, vPC, for example) STP
and its variants, its myriad knobs, UDLD, Bridge Assurance, LACP,
FHRP (VRRP, HSRP, GLBP), VTP, MVRP, etc. etc. Dual redundancy only
adds to the complexity mess Dual control planes HA ISSU etc.
Complex Failure Modes CORE L2 ACCESS L3 AGGREGATION 11. Twilight In
The Land of Godboxes Network's Function is to serve the application
needs Existing Network design is a bad fit for the modern DC
application 11 Image credit:
http://bestandworstever.blogspot.com/2012/07/best-lane-ending-sign-ever.html
12. cumulusnetworks.com 12 The Rise of the Modern Data Center
Networks 2.0: The New World Agenda 13. CLOS Network
cumulusnetworks.com 13 Invented by Charles Clos in 1953 How to
build ever larger telephony networks without building ever larger
telephony switches http://en.wikipedia.org/ wiki/Clos_network SPINE
LEAF 14. Characteristics Of CLOS Network cumulusnetworks.com Well
matched for E-W traffic pattern Scalable network topology Reliance
on ECMP leads to simple IP- based fabrics Fine grained failure
domain Predictable latency Coupled with network virtualization,
serves as a basis for agility and flexibility SPINE LEAF 14 15.
Scalable Network Topology 15cumulusnetworks.com 16. Some Common
Terminology 16cumulusnetworks.com CLUSTER or POD CLUSTER or POD
INTER-CLUSTER SPINE 17. Calculating Number of Attachable Servers:
Non-Blocking Math If m, n, o are number of ports on a switch at a
given tier Total number of servers attached to a 2-tier
fabric:m*n/2 Total number of servers attached to a 3-tier fabric:
m*n*o/4 cumulusnetworks.com 17 m n o 18. Port Math From A Different
Perspective Number of spines and ISL link speed is a function of
failure characteristics, cost and cabling simplification
cumulusnetworks.com 18 Number of pods/DC Number of servers/rack
Number of racks/pod 19. Calculating Number of Servers: Some
Concrete Numbers 2-tier 3-tier Theoretical Non-Blocking Trident+ 64
port 10GE 2K 64K Trident2 96 port 10GE 4608 216K More Pragmatic
Numbers: 40 servers/rack Trident+ (48x10GE, 4x40GE)
Oversubscription: 2.5 (with 4 spines) 1920 (40*48) 60K(40*24*6 4)
Trident2 (48x10GE, 6x40GE) Oversubscription: 1.6 1920 184K
cumulusnetworks.com 19 20. Paganini Variations
20cumulusnetworks.com 21. Fine Grained Failure Domain
cumulusnetworks.com 21 Any link or spine failure leads to only a
25% loss instead of 50% with traditional design Webscale companies
do 8-way and 16-way ECMP to mitigate single failure effects 22. The
Case for Simplicity Reduced number of protocols Single IP protocol
is sufficient No FHRP, STP, the myriad L2 variants
cumulusnetworks.com 22 23. Coda For The Godboxes All boxes are the
same Simplified inventory control Simplified management Reduced
latency compared to chassis-based boxes Simple 1RU boxes means
simple failures Replace failed box and continue instead of
debugging in place No ISSU, HA, etc. Developing new apps to run on
platform is simpler cumulusnetworks.com 23 24. What About Server
Attach Most, if not all, webscale companies do single attach They
have so many racks, failure of one doesnt bother them Smaller
enterprises that cannot sustain the loss of a rack dual-attach
servers Switches are in the same rack or cross connected pair of
racks cumulusnetworks.com 24 25. Does This Apply Only To Big Guys ?
Depends Many small guys are moving to cloud If the application
requirements are not L2-specific, this applies to small guys too
Simply think of the cost of bare metal switches to boxes from
traditional vendors Many small IT shops are run by Linux/server
admins Script savvy and so can setup networks faster More in next
webinar cumulusnetworks.com 25 26. Fitting Existing Applications:
Network Virtualization With network virtualization technologies
such as VxLAN, you can create L2 overlays over the L3 fabric
Separating virtual network from physical network provides for agile
network management Can run both new applications such as Hadoop and
memcached along with more traditional apps on the same network:
flexibility cumulusnetworks.com 26 27. And In Closing.. Existing
Access-Agg-Core design is slowly making way for CLOS fabrics CLOS,
L3-based fabrics are simple, scalable, flexible and agile Managing
a CLOS fabric including routing and such is the topic of the next
webinar cumulusnetworks.com 27 28. Resources available Website:
cumulusnetworks.com Blog: cumulusnetworks.com/blog Twitter:
@CumulusNetworks @ddcumulus cumulusnetworks.com 28 29. CUMULUS, the
Cumulus Logo, CUMULUS NETWORKS, and the Rocket Turtle Logo (the
Marks) are trademarks and service marks of Cumulus Networks, Inc.
in the U.S. and other countries. You are not permitted to use the
Marks without the prior written consent of Cumulus Networks. The
registered trademark Linux is used pursuant to a sublicense from
LMI, the exclusive licensee of Linus Torvalds, owner of the mark on
a world-wide basis. All other marks are used under fair use or
license from their respective owners. Thank You!
cumulusnetworks.com 29 Bringing the Linux Revolution to
Networking
