& cplSiteName &

Validating Cisco's NFV Infrastructure Pt. 1

Light Reading
Prime Reading
Light Reading
10/12/2015
100%
0%

Virtual switch FIB scalability

    Evaluation overview: In a pure virtual switching scenario, VPP showed no throughput degradation when forwarding to 2,000 IPv4 or Ethernet MAC addresses at 20 Gbit/s, less than 1% reduced throughput towards 20,000 MAC addresses and 23% reduced throughput when forwarding to 20,000 IP addresses. OVS IPv4 and Ethernet forwarding was reduced by 81% when forwarding to 2,000 IPv4 addresses.

Both previous scenarios focused exclusively on Ethernet layer throughput with a small number of flows because they both involved virtual machines. In the third scenario, we evaluated pure virtual switching without any actual application. This is, of course not a realistic application setup: instead it is a reference test of vSwitch properties that need to be determined independently of VNF performance.

One of the most basic and important scalability figures of an Ethernet switch is its ability to handle many Ethernet flows between different endpoints (associated with MAC addresses) in parallel. In a data center, there is usually much more East-West traffic between servers and services directly connected on the Ethernet segment than there is North-South traffic. vSwitches need to enable virtual services to participate in data center communication and need to be able to connect to many Ethernet destinations in parallel.

Separately, vSwitches obviously need to support many IP addresses in their forwarding information base table (FIB) simultaneously, when configured for IP forwarding. If traffic is routed towards a virtual firewall or a virtualized packet filter, there are usually tens of thousands of flows involved from thousands of IP addresses.

We verified forwarding performance of the standalone virtual switch with multiple layer 2/layer 3 FIB table sizes.

VPP showed its strengths based on the optimized, vector-based handling of large tables. It achieved very consistent IPv4 forwarding: The throughput was not dropped at all when forwarding to 2,000 IPv4 addresses compared to a single address scenario; throughput dropped only by 23 % when forwarding to 20,000 IPv4 addresses. The average forwarding latency was largely unaffected by the larger tables, and the maximum IPv4 forwarding latency was still bearable at 400 microseconds for 2,000 address entries and 1,200 microseconds for 20,000 entries.

In contrast, Open vSwitch seems to use less optimized FIB lookups. Throughput dropped from 20 Gbit/s (IPv4) and 8.8 Gbit/s (Ethernet) for the single-entry case down to around 4 Gbit/s in both cases for 2,000 IPv4 and MAC addresses. For 20,000 FIB entries the OVS-DPDK implementation was not usable in its current version as the throughput dropped to almost zero and maximum latency skyrocketed to 37 milliseconds (not microseconds!). We are not complaining -- after all, it's free software -- and in fact we hope that Cisco will contribute its VPP improvements back to OVS to improve the open source software.

These results indicate much better VPP performance in higher scale network deployments.

vSwitch-only IP forwarding performance.
vSwitch-only IP forwarding performance.

vSwitch-only Ethernet forwarding performance.
vSwitch-only Ethernet forwarding performance.

vSwitch-only latency performance.
vSwitch-only latency performance.

Next page: Evaluating the Cisco IOS XRv 9000

 
(3)  | 
Comment  | 
Print  | 
Newest First  |  Oldest First  |  Threaded View        ADD A COMMENT
Ray@LR
50%
50%
Ray@LR,
User Rank: Blogger
10/22/2015 | 12:03:34 PM
Re: Where is Part2
Part 2 is imminent.... a minor clarification neede dto be verified.

Thanks!
NPUArchi20846
100%
0%
NPUArchi20846,
User Rank: Light Beer
10/20/2015 | 5:25:21 PM
Where is Part2
"Part 2, which will be published on Monday October 19"
ashvin213
100%
0%
ashvin213,
User Rank: Light Beer
10/13/2015 | 12:12:27 AM
Some inconsistencies
Hi there,

 

I found some issues that I did not follow:

1.      Throughput in PPS and Gbps don't seem to match. For example, I do not understand how 2.2e6 fps translates to 7Gbps for large frames (it should be around 26Gbps).

2.      Even for small packets, the latencies are in us. Shouldn't they be in ns? The authors claim 20us is in line with ASIC based switches (which I don't think it is. Most hardware switches take a few ns to switch packets. For example, Trident-1 took around 600ns for L3 forwarding and 400ns for L2 forwarding. This was way back in 2009).

3. Adding more MAC addresses must simply increase the memory size. Given that all of these are exact-match tables, I fail to understand

Ashvin
Featured Video
From The Founder
Light Reading founder Steve Saunders talks with VMware's Shekar Ayyar, who explains why cloud architectures are becoming more distributed, what that means for workloads, and why telcos can still be significant cloud services players.
Flash Poll
Upcoming Live Events
May 14-16, 2018, Austin Convention Center
May 14, 2018, Brazos Hall, Austin, Texas
September 24-26, 2018, Westin Westminster, Denver
October 9, 2018, The Westin Times Square, New York
October 23, 2018, Georgia World Congress Centre, Atlanta, GA
November 7-8, 2018, London, United Kingdom
November 8, 2018, The Montcalm by Marble Arch, London
November 15, 2018, The Westin Times Square, New York
December 4-6, 2018, Lisbon, Portugal
All Upcoming Live Events
Hot Topics
I'm Back for the Future of Communications
Phil Harvey, US News Editor, 4/20/2018
BDAC Blowback – Ex-Chair Arrested
Mari Silbey, Senior Editor, Cable/Video, 4/17/2018
Verizon: Lack of Interoperability, Consistency Slows Automation
Carol Wilson, Editor-at-large, 4/18/2018
AT&T Exec Dishes That He's Not So Hot on Rival-Partner Comcast
Mari Silbey, Senior Editor, Cable/Video, 4/19/2018
Facebook Hearings Were the TIP of the Data Iceberg
Dan Jones, Mobile Editor, 4/20/2018
Animals with Phones
I Heard There Was a Dresscode... Click Here
Live Digital Audio

A CSP's digital transformation involves so much more than technology. Crucial – and often most challenging – is the cultural transformation that goes along with it. As Sigma's Chief Technology Officer, Catherine Michel has extensive experience with technology as she leads the company's entire product portfolio and strategy. But she's also no stranger to merging technology and culture, having taken a company — Tribold — from inception to acquisition (by Sigma in 2013), and she continues to advise service providers on how to drive their own transformations. This impressive female leader and vocal advocate for other women in the industry will join Women in Comms for a live radio show to discuss all things digital transformation, including the cultural transformation that goes along with it.

Like Us on Facebook
Twitter Feed