The document details the updates on SDN applications and the SwitchCloud project as of November 2014, including the progress of the 'bcc' cluster and future plans for network scalability. Challenges related to performance and missing features in OpenStack networking are discussed, with a focus on exploring SDN controller options and the necessity for an aggregation layer in cloud structures. The outlook emphasizes the ongoing evolution of the internet towards a cloud-integrated future, with significant developments in 5G and NFV anticipated.

1. SCALE/SWITCHengines Update
Current and Possible SDN Applications
SDN Workshop, Winterthur, 20 November 2014
Simon Leinen
simon.leinen@switch.ch

2. What happened since last time?
• Status at October 2013 SDN workshop presentation:
“Building Cloud – Where SDN Could Help”:
– Pilot OpenStack/Ceph cloud “BCC” existed
–New production cloud (2*2 racks) was planned
– SDN considered applicable for:
• Low-cost scalable internal fabric: whitebox ToR leaf/spine with multipath
• DC/Backbone interface without traditional $$ routers
• Tunneling towards customers for VPC (Virtual Private Cloud) offerings
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3. “BCC” Cluster – Still Running!
(for some value of…)-:
• Built ~10-node Ceph+OpenStack cluster
BCC – “building cloud competence”
• Services:
– VMs for various researchers and internal testers
– File synchronization server for ~3’500 end users
of SWITCHdrive service
• Networking:
–2*10GE per server
– 6*10GE on front-end servers, which route
– Two Brocade “ToR” switches with TRILL-based
multi-chassis multipath, L2+VLANs
– 2*10GE towards backbone
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4. Pilot  SWITCH Cloud Project  SCALE
Co-funded (50% of manpower) by CUS P-2 program
“Information scientifique – accès, traitement et sauvegarde”
Project SCALE, May 2014 – May 2015
• Two sites: UniL Géopolis, ZHdK Toni-Areal, each with
– 32 (16 compute+16 storage) 2U servers w/2*10GE each
– 2*10GE external connectivity (pending 2nd link @Toni-Areal)
– room for growth to ~20 racks
• New “SWITCHengines” IaaS offering, in limited testing
now
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5. SCALE Networking
• Hardware: Two ToRs (Brocade ICX 48*10GE,6*40GE)
–External: BGP peerings (IPv4+IPv6) to backbone routers
– Internal: Redundant connections to servers (802.1ad), mult. VLANs
– Interconnected with single 40GE link
–Router connections optical, all others DAC (direct-attach copper)
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6. SCALE Networking: Software
• OpenStack “Icehouse” (2014.1)
–Neutron (OpenStack Networking), standard/open-source components:
• ML2 (Modular Layer-2) plugin
• Open vSwitch (OVS)
• VXLAN overlay for tenant network isolation
• Setup:
–Two OpenStack regions LS/ZH (each with its own Ceph cluster)
– Single “network node” (VM!) per region for virtual L3 routing
• between tenant (virtual) networks
• between VMs and Internet
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7. Neutron
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8. Neutron
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9. Neutron
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10. Problems: MTU (solved)
• In the default configuration, usable MTU in tenant (overlay)
networks is 14xx bytes
• So, “ping” works, but “apt-get update” hangs…
• Everybody (who uses ML2/OVS/VXLAN) has this problem!
• Default way to “fix” this is to lower client (VM) MTU
– IMHO this is hopeless – 1500 bytes much too ingrained now
• We increase underlay MTU instead (to 1600) - much better

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11. Problems: Performance
• Single-stream performance VM <-> Internet ~1.5Gb/s
– Should be close to 10Gb/s
• Many possible bottlenecks:
– Single network node (will get better with DVR in OpenStack Juno)
–Virtualized network node (could be un-virtualized if necessary)
–OVS overhead (will get better with new versions, e.g. zero-copy)
–VXLAN overhead (will get better with kernel versions, possibly
hardware support with future Ethernet adapters)
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12. Problems: Missing features
• IPv6 for VMs
– “hopefully in Juno” (not really a Neutron issue?)
• VPC (VPNning back into customers’ campus LANs)
–To be added in the longer term (IT needs more than researchers?)
• LBaaS (OpenStack-integrated Load Balancer)
– Should be easy to add
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13. Move to “real” SDN controller?
• But there are so many to choose from!
– Nicira N$X
–OpenContrail (open source, uses MPLS, Juniper base)
– Midokura/MidoNet (open source since this month! EPFL ties)
–Nuage (uses MPLS, Alcatel-Lucent/TiMetra base)
–Open Daylight (but what does it do?)
–Calico (open source, Metaswitch base, L3-based, even does IPv6)
– Plumgrid, …
– Snabb NFV! (open source, hackable, high-performance user-space)
• …or should we just wait until the market sorts this out?
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14. Growing the Cloud: Internal fabric
• Beyond a few racks, we need some sort of “aggregation
layer” beyond the ToR. There are multiple approaches:
–Traditional with large aggregation switch (doubled for redundancy)
– Modern with leaf/spine design <- cost-effective “commodity” kit
• How can servers make use of parallelism in the fabric?
– Smart L2 switches (TRILL, Multi-chassis LAG etc.) – vendor lock-in?
– L3 switches with hypervisor-based overlay à la Nicira OVP
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15. New HW/SW options for leaf/spine
• “White-box” ToR switches sold without OS (just OPIE)
– e.g. 32-port 40GE <CHF 10’000
• Run e.g. Cumulus Networks (Linux) on them
–Could use Puppet to provision = same as servers
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16. What Became of “Future Internet”?
“The Internet has a great future behind it”- Jon Crowcroft
Big funding drive since ~2007 in US and EU (and…)
• Clean slate / greenfield / disruptive thinking
• Radical new (or old) ideas (e.g. ICN)
• Testbeds!
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17. What Became of “Future Internet”?
• In 2014:
– EU held last Future Internet Assembly
– Moving towards new horizons, e.g. 5G
• FI-PPP still running – see 5 December event @ZHAW
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18. What Became of “Future Internet”?
• In 2014:
– EU held last Future Internet Assembly
– Moving towards new horizons, e.g. 5G
• FI-PPP still running – see 5 December event @ZHAW
Hypothesis:
Future Internet = Current Internet + Cloud
• as new generative platform (cf. FI-Labs)
• to save Telcos (NFV)
Future of Cloud (incl. NFV) = OpenStack
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