INTRODUCTIONSoftware-Defined Networking (SDN) and Network Function Virtualization (NFV) are fundamentally transforming data networks by disaggregating vertically integrated boxes, thereby unleashing new innovation. These next-generation networks are more complex in nature and require better vis-ibility at various levels to satisfy SLAs. Centraliz-ing the control plane, at least logically, is creating new business opportunities in monitoring and optimizing resources at the network level.

Network analytics enable service providers and enterprises better insight into their network usage. Improved visibility into various traffic flows pro-vides new opportunities to optimally monetize the network. Ensuring superior network performance for higher revenue-generating flows results in bet-ter and faster ROI for these companies. Tradi-tional methods of network capacity planning and deployment that are done in a static manner are no longer suited to today's dynamic workloads driven by virtualization, multi-tenancy, and next-gen services. Continuous monitoring, analysis, and optimization are essential in meeting the competitive demands on today’s networks. But many analytics solutions are reactive in nature and often involve manual analysis of complex traf-fic flows, which is slow by nature. Moreover, the amount of information collected and metrics gath-ered is growing exponentially. Monitoring product vendors are scrambling to provide new solutions to deal with the unprecedented volume of data and provide useful information in a timely manner. All these solutions are limited by the data exposed by the silicon in the forwarding plane. In addition, service providers are pushing for open-source commitment to reduce vendor lock-in and increase innovation.

Broadcom recognized the need for improved visi-bility in next-generation networks and has become a leader in the ecosystem by initiating several solutions well in advance of industry demands. Breaking from the tradition, Broadcom began offering open-source software and built ref-erence applications to demonstrate the use cases in an end-to-end manner. More and more metrics are being opened up to support an increased number of use cases and stimulate innovation in the analytics space. With innovative features such as threshold-based monitoring, Broadcom’s BroadView instrumentation software is a unique solution that delivers proactive analysis in a scal-able manner. In addition, BroadView further enhances the solution by abstracting and aggre-gating analytics data before exporting in an appli-cation-friendly REST API. By providing a common visibility API, Broadcom enables ISVs to develop their applications one time across multiple plat-forms and OSs. Additional Northbound Interface (NBI) technologies such as sFlow are planned to be supported for easier integration into Network Management Systems. Broadcom is also actively working with various participants in the SDN/NFV ecosystem in making the BroadView solution ubiquitous in a wide range of carrier and enter-prise networks. Complemented by silicon-sup-ported features such as timestamping, dedicated statistics interfaces, and direct support for mirror-to ports, BroadView is positioned to significantly improve how analytics are done and make net-works even smarter and more efficient.

BroadView technology is a collection of features that enable:

• Smarter Analytics

• Packet Tracing (PT) and Injection

The BroadView software package provides the BroadView APIs, documentation, and example applications that enable customers to create their own innovative solutions.

Next-generation networks driven by Software Defined Networking (SDN) and virtualization are becoming more and more com-plex, as companies move away from vertically integrated boxes to disaggregated networks sup-ported by a multitude of vendors and technologies.

Carriers are pushing for open-source based platforms like those tested and proven by some major enterprises in their in-house networks.

These trends are demanding increased visibility into the net-work to satisfy customer SLAs and capitalize on the new oppor-tunities created by these new technologies.

BroadView™ instrumentation software from Broadcom® offers new solutions to meet these challenges by making analytics smarter and offering better packet tracing capabilities.

Overview

STRATASWITCH TECHNICAL BRIEF

BroadViewOverview of BroadView™ Instrumentation Software

SMARTER ANALYTICSBroadView provides many features to enable smarter analytics. Features such as Buffer Statistics Tracking, headroom usage, and timing awareness provide unprecedented visibility and enable better control over the internals of the switch state, thereby leading to smarter analytics.

BUFFER STATISTICS TRACK-INGBuffer Statistics Tracking (BST) is one of the most important features for enabling rich congestion analytics. Network Traffic is bursty by nature and microbursts occur when there is transient congestion. Micro-bursts are difficult to detect using tradi-tional port drop counts. Broadcom silicon provides the ability to monitor MMU buffer utilization counts as part of the BST fea-ture. It provides network administrators and applications improved telemetry on the usage of various ingress and egress buffers, without disrupting regular packet forwarding operations. There are thou-

sands of counters available across vari-ous ports, port groups, and service pools that can be utilized by the applications for instantaneous monitoring in a scalable way.

BST tracks ingress-, egress-, and device-based use-counts for both unicast and multicast flows. The actual use-counts vary depending on the chip set. Two types of tracking are supported:

• Current or Instantaneous: Updates counters as and when packets are en-queued and de-queued.

• Peak: Updates counters only when the current value exceeds the previously recorded maximum or peak value.

BST is significantly different and better than polling. Polling is a mechanism driven by software, where statistics are collected at certain predefined intervals. This approach is reactive in nature and does not scale well. Polling-based schemes usually are not very efficient at detecting and preventing congestion, as

congestion events can be missed, and fre-quent polling taxes the CPU and the CPU interface to the silicon. BST feature pro-vides a threshold-based trigger, thereby avoiding the need for frequent polling of MMU counters.

BST-enabled applications define a config-urable threshold for a use-count and trig-ger a CPU interrupt when the threshold is crossed. In addition to identifying the use-count that exceeded the threshold, BST also provides a snapshot of various statis-tics, thereby enabling the application to gain valuable and precise information about the network state. By defining appropriate thresholds, in most of the deployment scenarios, applications can predict congestion proactively. BST pro-vides an efficient and scalable way to detect, predict, and plan for congestions (and microbursts), thereby allowing opera-tors to better tune their networks to meet customer SLAs and improve the Quality of Experience (QoE).

Buffer Statistics Tracking Flow

Data Plane

SDN Controller

Application A Application B

Software Updates 4 Computers

Unauthorized Applications 20 Computers

Audit Status

4 Computers

Analyze

Automate

Monitor

Optimize

PACKET TRACINGBroadView's Packet Tracing feature enables applications to gain deeper insight into the internal state of a switch. Using this feature, applications can inject a purpose-built packet and get detailed information on how the packet is pro-cessed through the ingress pipeline. In addition to specifying the logical ingress port number, the custom-built packet can be created by specifying any of the follow-ing:

• L2, L3, L4 header for Ethernet IP packet

• Outside tunnel header, Inside packet header

• MPLS labels + Payload + Packet Len

• PCAP file format

The silicon recognizes the special packet, captures detailed information of the packet traversal, and provides metadata. Addi-tional details such as ECMP/LAG resolu-tion and counters are also captured. The Packet Trace packet can be either dropped or forwarded on the wire depend-ing on the application configuration. Appli-cations can also request a copy of a dropped packet for a preselected list of drop reasons.

One data center technology that the packet trace feature helps to simplify is overlay networks. Through Packet Trac-ing, applications get detailed information on how overlay packets are mapped and forwarded on various underlay links.

INSTRUMENTATION AGENTThe BroadView instrumentation agent is the central piece of software that bundles all BroadView features into a standard Linux daemon and exposes them to appli-cations through a standard NBI. The BroadView agent and reference applica-tions are available in Open Source to spur adoption of silicon capabilities and to encourage innovation by inspiring new applications. The agent was designed in a modular way to enable easier extension and customization as needed for integra-tion into a target network OS. The agent uses a minimal configuration read from a configuration file for connecting with the application/collector on the Northbound interface.

The BroadView instrumentation agent consists of the following four major func-tional blocks

1. Northbound Block: The North-bound Plugin block manages con-nectivity with the applications/controllers that interface with the BroadView agent. Discovery, Secu-rity, and Load Balancer are major functional modules within this block. The distribution comes with a default implementation that can be easily extended.

2. Instrumentation Block: This block consists of all the functional modules that register with the infrastructure during startup. As the features sup-ported depend on the underlying sili-con, the functional blocks register the underlying silicon and supported API during startup.

3. Southbound Block: This block con-sists of different plugin modules to support different SB-API specifica-tions. The SB-Plugin redirector com-ponent maps the incoming instrumentation component requests to the corresponding Plug-in compo-nent.

4. Infrastructure Block: This block consists of necessary infrastructure and utilities for the other modules in the agent. The module manager component maps incoming REST APIs to the appropriate handler function based on the information provided by the instrumentation blocks during registration time. The logging component is self-explana-tory. The system component man-ages other components based on the configuration and provides time- based services such as periodic col-lection of statistics.

For detailed information, refer to the “Soft-ware Overview” section in the BroadView documentation.

Packet Trace in Overlay Networks – Example

The BroadView distribution also provides basic implementation for some applica-tions as a reference.

BST Application: The reference BST application communicates with the Broad-View agent via a REST API to configure the BST feature. The reference applica-tion enables the BST feature, clears BST statistics, and configures the software to receive BST data/reports from the agent through asynchronous messages at regu-lar intervals. The reference application is configured to exit after receiving a config-ured maximum number of reports. The BST application demonstrates how the BroadView agent facilitates analytics applications in gathering data from the sili-con in a scalable and application-friendly manner.

Packet Trace (PT) Application: The ref-erence PT application provides a mecha-nism to create a trace packet, inject it into the CPU masquerade port and get the trace profile for the injected packet. The BroadView agent is configured through the “drivshell” prompt that can be accessed by running the agent in debug mode. The PT application provides a com-mand-line interface (CLI) menu for invok-ing various features of the application. The PT application provides command-line options either to create the entire packet header by configuring each field on the CLI or to specify a pcap filename which contains the entire packet header.

The CLI also enables the user to configure whether the packet trace should be gener-ated at a regular interval and whether the trace packet should be dropped or for-warded on the wire after the trace profile was captured. The PT application commu-nicates with the BroadView agent via a REST API and stores the received trace profile in a log file.

Reference Applications

BroadView Instrumentation Agent

BST App PacketTrace App Other App

REST

RESTWeb

ServerDiscovery Security Load

Balancer Logger

System

Module Manager

C-JSON

...Buffer Monitor

Packet TracerBST

SB-Plugin Redirector

Open NSL SB Plugin SDK SB Plugin

© 2016 Broadcom. All rights reserved. Broadcom®, the pulse logo, Connecting everything®, the Connecting everything logo, and Avago Technologies are among the trademarks of Broadcom and/or its affiliates in the United States, certain other countries and/or the EU. Any other trademarks or trade names mentioned are the property of their respective owners. Broadcom reserves the right to make changes without further notice to any products or data herein to improve reliability, function, or design.

ABOUT BROADCOMBroadcom (NASDAQ: AVGO) is a diversified global semiconductor leader built on 50 years of innovation, collaboration and engineering excellence. Broadcom’s extensive product portfolio serves multiple applications within four primary end markets: wired infrastructure, wireless communications, enterprise storage and industrial & others. Broadcom is changing the world by Connecting everything®. For more information, go to www.broadcom.com.BroadView-TB101-R • March 18, 2016