Network Working Group T. Kim
Internet-Draft E. Paik
Intended status: Informational KT
Expires: September 22, 2016 March 21, 2016

Considerations for Benchmarking High Availability of NFV Infrastructure


This documents lists additional considerations and strategies for benchmarking high availability of NFV infrastructure when network functions are virtualized and performed in NFV infrastructure.

Requirements Language

The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in RFC 2119 [RFC2119].

Status of This Memo

This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79.

Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet-Drafts is at

Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress."

This Internet-Draft will expire on September 22, 2016.

Copyright Notice

Copyright (c) 2016 IETF Trust and the persons identified as the document authors. All rights reserved.

This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents ( in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License.

Table of Contents

1. Introduction

As both the amount and variety of traffic massively increase, operators are adopting SDN and NFV, the new paradigm of networking, in order to secure scalability and flexibility. Service providers and venders are developing SDN and NFV solutions to reduce CAPEX and OPEX, focusing on the increment of the scalability and flexibility of the network with programmable networking.

While VNF and NFVI replacing the legacy network devices and operators selecting the fittest one from various products, operators have several issues such as availability, resiliency and immeasurable failures. Above all, they want to ensure the availability of the VNF products and their infrastructures.

Customer expectations on the availability of service are as high as five 9s on any infrastructure operators offer because the standard availability of 4G mobile communication on the legacy physical network among operators has been already five 9s; downtime being 5.26 minutes per year. Therefore, to meet the customer expectations, services on the NFV infrastructure also need to meet the availability to that level, five 9s. Furthermore, the availability of NFV infrastructure needs to be almost six 9s with the consideration of the impact of virtualization and interoperability among different vendor solutions and layers. From the operator point of view, the availability is the most important feature and the benchmarking tests for the high availability of NFV infrastructure are also important. This document investigates considerations for high availability of NFV Infrastructure benchmarking test.

2. Considerations for Benchmarking High Availability of NFV Infrastructure

This section defines and lists considerations which must be addressed to benchmark the high availability of the NFV infrastructure.

2.1. Definitions for High Availability Benchmarking Test

Metrics for high availability Benchmarking of NFV infrastructure are as follows.

Generally, availability and failure rates are defined as follows, where MTBF stands for Mean Time Between Failure and MTTR stands for Mean Time To Recovery.

Availability : MTBF / (MTBF + MTTR)

Failure Rates : 1 - Availability

A failover procedure in an infrastructure is as follows.

Failure -> Failure Detection -> Isolation -> Recovery, therefore failover time starts from the time when a failure happens.

2.2. Configuration Parameters for Benchmarking Test

 +---------------+		     +---------------+
 | vCPU for VNF1 |		     |	 	     |
 +---------------+		     | vCPU for VNF2 |
 +---------------+		     |	      	     | +---------------+
 | vCPU for VNF2 |		     +---------------+ | vCPU for VNF1 |
 +---------------+				       +---------------+
 +---------------+ +---------------+ +---------------+ +---------------+
 | vCPU for VNF3 | | vCPU for VNF2 | | vCPU for VNF3 | | vCPU for VNF3 |
 +---------------+ +---------------+ +---------------+ +---------------+
 +---------------+ +---------------+ +---------------+ +---------------+	
 |     pCPU 1	 | |	 pCPU 2	   | |    pCPU 3     | |    pCPU 4     |	
 +---------------+ +---------------+ +---------------+ +---------------+		

3. High Availability Benchmarking test strategies

This section discusses benchmarking test strategies for high availability of NFV infrastructure. For the continuity of the services, followings needs to be considered.

3.1. Single Point of Failure Check

All devices and software have potential failures, therefore, redundancy is mandatory. First, the redundancy implementation of every sing point of NFV infrastructure must be tested as shown below.

 | Physical Machine						|	
 |								|
 |								| 
 |  +--------------------------------------------------------+  |
 |  |		    Virtual Network Function	    	     |  |
 |  +--------------------------------------------------------+  |
 |  +--------------------------------------------------------+  |		
 |  |			Virtual Machine		 	     |  |
 |  +--------------------------------------------------------+  |
 |  +--------------------------------------------------------+  |
 |  |			Virtual Bridge		   	     |  |
 |  +--------------------------------------------------------+  |		 
 |  +--------------------------------------------------------+  |	
 |  |			   Hypervisor		 	     |  |  
 |  +--------------------------------------------------------+  |
 |  +--------------------------------------------------------+  |
 |  |			Operating System		     |  | 
 |  +--------------------------------------------------------+  |
 |  +--------------------------------------------------------+  |
 |  |	 	     	Generic Hardware		     |  | 
 |  +--------------------------------------------------------+  |

3.2. Failover Time Check

Even though the components of NFV infrastructure are redundant, failover time can be long. For example, when a failure happens, the VNF with failure stops and should be replaced by backup VNF but the time to be shifted to the new VNF can be varied with the VNF; stateless or stateful. Namely, redundancy does not guarantees high availability and short failover time is required to reach high availability. This section discusses strategy about measuring failover time.

In order to measure the failover time presicely, the time when failure happens must be defined. Followings are three different criteria which is the time when failure happens.

  1. The time starts when failure actually happens
  2. The time starts when failure detected by manager or controller
  3. The time starts when failure event alerts to the operator

As the actual operations in VNFs and NFV infrastructure start to be changed when failure happens, the precise time of the failure happened must be the 1. When measuring the failover time, it starts from the time when the failures happens at a point in NFV infrastructure or VNF itself.

4. Security Considerations


5. IANA Considerations

No IANA Action is requested at this time.

6. Normative References

[NFV.REL001] , , "Network Function Virtualization: Resiliency Requirements", Group Specification ETSI GS NFV-REL 001 V1.1.1 (2015-01), January 2015.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997.

Authors' Addresses

Taekhee Kim KT Infra R&D Lab. KT 17 Woomyeon-dong, Seocho-gu Seoul, 137-792 Korea Phone: +82-2-526-6688 Fax: +82-2-526-5200 EMail:
EunKyoung Paik KT Infra R&D Lab. KT 17 Woomyeon-dong, Seocho-gu Seoul, 137-792 Korea Phone: +82-2-526-5233 Fax: +82-2-526-5200 EMail: URI: