Archive

Category Archives for "sFlow"

Internet eXchange Provider (IXP) Metrics

IXP Metrics is available on Github. The application provides real-time monitoring of traffic between members of an Internet eXchange Provider (IXP) network.

This article will use Arista switches as an example to illustrate the steps needed to deploy the monitoring solution, however, these steps should work for other network equipment vendors (provided you modify the vendor specific elements in this example).

git clone https://github.com/sflow-rt/prometheus-grafana.git
cd prometheus-grafana
env RT_IMAGE=ixp-metrics ./start.sh

The easiest way to get started is to use Docker, see Deploy real-time network dashboards using Docker compose, and deploy the sflow/ixp-metrics image bundling the IXP Metrics application.

scrape_configs:
  - job_name: sflow-rt-ixp-metrics
    metrics_path: /app/ixp-metrics/scripts/metrics.js/prometheus/txt
    static_configs:
    - targets: ['sflow-rt:8008']
Follow the directions in the article to add a Prometheus scrape task to retrieve the metrics.
sflow source-interface management 1
sflow destination 10.0.0.50
sflow polling-interval 20
sflow sample 50000
sflow run

Enable sFlow on all exchange switches, directing sFlow telemetry to the Docker host (in this case 10.0.0.50).

Use the sFlow-RT Status page to confirm that sFlow is being received from the switches. In this case 286 sFlow datagrams per second are being received from 9 switches.
The IX-F Member Export JSON Schema Continue reading

Containerlab dashboard

The GitHub sflow-rt/containerlab project contains example network topologies for the Containerlab network emulation tool that demonstrate real-time streaming telemetry in realistic data center topologies and network configurations. The examples use the same FRRouting (FRR) engine that is part of SONiC, NVIDIA Cumulus Linux, and DENT network operating systems. Containerlab can be used to experiment before deploying solutions into production. Examples include: tracing ECMP flows in leaf and spine topologies, EVPN visibility, and automated DDoS mitigation using BGP Flowspec and RTBH controls.
The screen capture at the top of this article shows a real-time dashboard displaying up to the second traffic analytics gathered from the 5 stage Clos fabric shown above. This article walks through the steps needed to run the example.
git clone https://github.com/sflow-rt/containerlab.git
cd containerlab
./run-clab
Run the above commands to download the project and run Containerlab on a system with Docker installed. Docker Desktop is a conventient way to run the labs on a laptop.
containerlab deploy -t clos5.yml
Start the emulation.
./topo.py clab-clos5
Post topology to sFlow-RT REST API. Connect to http://localhost:8008/app/containerlab-dashboard/html/ to access the Dashboard shown at the top of this article.
docker exec -it clab-clos5-h1 iperf3 -c 172.16. Continue reading

Grafana Network Weathermap

The screen capture above shows a simple network weathermap, displaying a network topology with links animated by real-time network analytics.
Hovering over a link in the weathermap pops up a trend chart showing traffic on the link over the last 30 minutes.

Deploy real-time network dashboards using Docker compose, describes how to quickly deploy a real-time network analytics stack that includes the sFlow-RT analytics engine, Prometheus time series database, and Grafana to create dashboards. This article describes how to extend the example using the Grafana Network Weathermap Plugin to display network topologies like the ones shown here.

First, add a dashboard panel and select the Network Weathermap visualization. Next define the three metrics shown above. The ifinoctets and ifoutoctets need to be scaled by 8 to convert from bytes per second to bits per second. Creating a custom legend entry makes it easier to select metrics to associate metric instances with weathermap links.
Add a color scale that will be used to color links by link utilization. Defining the scale first ensures that links will be displayed correctly when they are added later.
Add the nodes to the canvas and drag them to their desired locations. There is a Continue reading

Deploy real-time network dashboards using Docker compose


This article demonstrates how to use docker compose to quickly deploy a real-time network analytics stack that includes the sFlow-RT analytics engine, Prometheus time series database, and Grafana to create dashboards.
git clone https://github.com/sflow-rt/prometheus-grafana.git
cd prometheus-grafana
./start.sh
Download the sflow-rt/prometheus-grafana project from GitHub on a system with Docker installed and start the containers. The start.sh script runs docker compose to bring up the containers specified in the compose.yml file, passing in user information so that the containers have correct permission to  write data files in the prometheus and grafana directories.
All the Docker images in this example are available for both x86 and ARM processors, so this stack can be deployed on Intel/AMD platforms as well as Apple M1/M2 or Raspberry Pi. Raspberry Pi 4 real-time network analytics describes how to configure a Raspberry Pi 4 to run Docker and perform real-time network analytics and is a simple way to run this stack for smaller networks.

Configure sFlow Agents in network devices to stream sFlow telemetry to the host running the analytics stack. See Getting Started for information on how to verify that sFlow telemetry is being received.

Connect to the Grafana web interface on Continue reading

Raspberry Pi 4 real-time network analytics

CanaKit Raspberry Pi 4 EXTREME Kit - Aluminum
This article describes how build an inexpensive Raspberry Pi 4 based server for real-time flow analytics of industry standard sFlow streaming telemetry. Support for sFlow is widely implemented in datacenter equipment from vendors including: A10, Arista, Aruba, Cisco, Edge-Core, Extreme, Huawei, Juniper, NEC, Netgear, Nokia, NVIDIA, Quanta, and ZTE.

In this example, we will use an 8G Raspberry Pi 4 running Raspberry Pi OS Lite (64-bit).  The easiest way to format a memory card and install the operating system is to use the Raspberry Pi Imager (shown above).
Click on the gear icon to set a user and password and enable ssh access. These initial settings allow the Rasberry Pi to be accessed over the network without having to attach a screen, keyboard, and mouse.

Next, follow instruction for installing Docker Engine (Raspberry Pi OS Lite is based on Debian 11).

The diagram shows how the sFlow-RT real-time analytics engine receives a continuous telemetry stream from industry standard sFlow instrumentation build into network, server and application infrastructure and delivers analytics through APIs and can easily be integrated with a wide variety of on-site and cloud, orchestration, DevOps and Software Defined Networking Continue reading

Leaf and spine network emulation on Mac OS M1/M2 systems


The GitHub sflow-rt/containerlab project contains example network topologies for the Containerlab network emulation tool that demonstrate real-time streaming telemetry in realistic data center topologies and network configurations. The examples use the same FRRouting (FRR) engine that is part of SONiC, NVIDIA Cumulus Linux, and DENT network operating systems. Containerlab can be used to experiment before deploying solutions into production. Examples include: tracing ECMP flows in leaf and spine topologies, EVPN visibility, and automated DDoS mitigation using BGP Flowspec and RTBH controls.

The Containerlab project currently has limited support for Mac OS, stating "ARM-based Macs (M1/2) are not supported, and no binaries are generated for this platform. This is mainly due to the lack of network images built for arm64 architecture as of now." However, this argument doesn't apply to the Linux based images used in these examples.

First install Docker Desktop on your Apple silicon based Mac (select the Apple Chip option).

mkdir clab
cd clab
docker run --rm -it --privileged \
  --network host --pid="host" \
  -v /var/run/docker.sock:/var/run/docker.sock \
  -v /run/netns:/run/netns \
  -v $(pwd):$(pwd) -w $(pwd) \
  sflow/clab bash

Run Containerlab by typing the above commands in a terminal. This command uses a pre-built multi-architecture Continue reading

VyOS DDoS mitigation

Real-time flow analytics on VyOS describes how to install real-time analytics based on sFlow and the sFlow-RT analytics engine. This article extends the example to show how to automatically mitigate DDoS attacks using flow analytics combined with BGP Remotely Triggered Black Hole (RTBH) / Flowspec.
vyos@vyos:~$ add container image sflow/ddos-protect
First, download the sflow/ddos-protect image.
vyos@vyos:~$ mkdir -m 777 /config/sflow-rt
Create a directory to store persistent container state.
set container network sflowrt prefix 192.168.1.0/24
Define an internal network to connect to container. Currently VyOS BGP does not allow direct connections to local addresses (e.g. 127.0.0.1), so we need to put controller on its own network so the router can connect and receive DDoS mitigation BGP RTBH / Flowspec controls.
set container name sflow-rt image sflow/ddos-protect
set container name sflow-rt host-name sflow-rt
set container name sflow-rt arguments '-Dddos_protect.router=192.168.1.1 -Dddos_protect.enable.flowspec=yes'
set container name sflow-rt environment RTMEM value 200M
set container name sflow-rt memory 0
set container name sflow-rt volume store source /config/sflow-rt
set container name sflow-rt volume store destination /sflow-rt/store
set container name sflow-rt network sflowrt address 192.168.1.2

Configure a container to run the image. The Continue reading

Real-time flow analytics on VyOS

VyOS with Host sFlow agent describes support for streaming sFlow telemetry added to the open source VyOS router operating system. This article describes how to install analytics software on a VyOS router by configuring a container.
vyos@vyos:~$ add container image sflow/ddos-protect
First, download the sflow/ddos-protect image.
vyos@vyos:~$ mkdir -m 777 /config/sflow-rt
Create a directory to store persistent container state.
set container name sflow-rt image sflow/ddos-protect
set container name sflow-rt allow-host-networks
set container name sflow-rt arguments '-Dhttp.hostname=10.0.0.240'
set container name sflow-rt environment RTMEM value 200M
set container name sflow-rt memory 0
set container name sflow-rt volume store source /config/sflow-rt
set container name sflow-rt volume store destination /sflow-rt/store
Configure a container to run the image. The RMEM environment variable setting limits the amount of memory that the container will use to 200M bytes. The -Dhttp.hostname argument sets the internal web server to listen on management address, 10.0.0.240, assigned to eth0 on this router. The container has is no built-in authentication, so access needs to be limited using an ACL or through a reverse proxy - see Download and install.
set system sflow interface eth0
set system sflow interface eth1
set system sflow interface  Continue reading

Dropped packet reason codes in VyOS

The article VyOS with Host sFlow agent describes how to use industry standard sFlow telemetry to monitor network traffic flows and statistics in the latest VyOS rolling releases. VyOS dropped packet notifications describes how sFlow also provides visibility into network packet drops and Dropped packet reason codes in Linux 6+ kernels describes how newer kernels are able to provide specific reasons for dropping packets. 
vyos@vyos:~$ uname -r
6.1.22-amd64-vyos

The latest VyOS rolling release runs on a Linux 6.1 kernel and the latest release of VyOS now provides enhanced visibility into dropped packets using kernel reason codes.

vyos@vyos:~$ show version
Version:          VyOS 1.4-rolling-202303310716
Release train:    current

Built by:         [email protected]
Built on:         Fri 31 Mar 2023 07:16 UTC
Build UUID:       1a7448d9-d53c-48a0-8644-ed1970c1abb8
Build commit ID:  75c9311fba375e

Architecture:     x86_64
Boot via:         installed image
System type:       guest

Hardware vendor:  innotek GmbH
Hardware model:   VirtualBox
Hardware S/N:     0
Hardware UUID:    da75808d-ff60-1d4c-babd-84a7fa341053

Copyright:        VyOS maintainers and contributors
Verify that the version of of VyOS is VyOS 1.4-rolling-202303310716 or later.

In the previous article, VyOS dropped packet notifications,  two tests were performed, the first a failed attempt to connect to the VyOS router using telnet (telnet has been disabled in Continue reading

Dropped packet reason codes in Linux 6+ kernels

Using sFlow to monitor dropped packets describes support for standard sFlow Dropped Packet Notications in the open source Host sFlow agent. This article describes additional capabilities in Linux 6+ kernels that clarify reasons why packets are dropped in the kernel.

The recent addition of dropreason.h in Linux 6+ kernels provides detailed reasons for packet drops. The netlink drop_monitor API has been extended to include the NET_DM_ATTR_REASON attribute to report the drop reason, see net_dropmon.h.

The following example illustrates the value of the reason code in explaining Linux packet drops.

tcp_v4_rcv+0x7c/0xef0
The value of NET_DM_ATTR_SYMBOL shown above indicates that the packet was dropped in the tcp_v4_rcv function in Linux kernel at memory location 0x7c/0xef0. While this information is helpful, there are many reasons why a TCP packet may be dropped.
NO_SOCKET
In this case, the value of NET_DM_ATTR_REASON shown above indicates that the TCP packet was dropped because no application had opened a socket and so there was nowhere to deliver the packet.

In the case of Linux-based hardware switches or smart network adapters, where packet processing is offloaded to hardware, the netlink drop_monitor events include NET_DM_ATTR_HW_TRAP_GROUP_NAME and NET_DM_ATTR_HW_TRAP_NAME attributes and packet header information supplied by the hardware Continue reading

VyOS dropped packet notifications

VyOS with Host sFlow agent describes how to configure and analyze industry standard sFlow telemetry recently added to the VyOS open source router platform. This article discusses sFlow dropped packet notifications support added to the latest release.

Dropped packets have a profound impact on network performance and availability. Packet discards due to congestion can significantly impact application performance. Dropped packets due to black hole routes, expired TTLs, MTU mismatches, etc. can result in insidious connection failures that are time consuming and difficult to diagnose. Visibility into dropped packets offers significant benefits for network troubleshooting, providing real-time network-wide visibility into the specific packets that were dropped as well the reason the packet was dropped. This visibility instantly reveals the root cause of drops and the impacted connections.

vyos@vyos:~$ show version
Version: VyOS 1.4-rolling-202303260914
Release train: current

Built by: [email protected]
Built on: Sun 26 Mar 2023 09:14 UTC
Build UUID: 72b34f74-bfcd-4b51-9b95-544319c2dac5
Build commit ID: d68bda6a295ba9

Architecture: x86_64
Boot via: installed image
System type: guest

Hardware vendor: innotek GmbH
Hardware model: VirtualBox
Hardware S/N: 0
Hardware UUID: df0a2b79-b8c4-8342-a27f-76aa3e52ad6d

Copyright: VyOS maintainers and contributors

Verify that the version of of VyOS is VyOS 1.4-rolling-202303260914 or later.

On VyOS dropped packet monitoring Continue reading

VyOS with Host sFlow agent

VyOS described deficiencies with the embedded sFlow implementation in the open source VyOS router operating system and suggested that the open source Host sFlow agent be installed as an alternative. The VyOS developer community embraced the suggestion and has been incredibly responsive,  integrating, and releasing a version of VyOS with Host sFlow support within a week.
vyos@vyos:~$ show version
Version: VyOS 1.4-rolling-202303170317
Release train: current

Built by: [email protected]
Built on: Fri 17 Mar 2023 03:17 UTC
Build UUID: 45391302-1240-4cc7-95a8-da8ee6390765
Build commit ID: e887f582cfd7de

Architecture: x86_64
Boot via: installed image
System type: guest

Hardware vendor: innotek GmbH
Hardware model: VirtualBox
Hardware S/N: 0
Hardware UUID: 871dd0f0-c4ec-f147-b1a7-ed536511f141

Copyright: VyOS maintainers and contributors
Verify that the version of of VyOS is VyOS 1.4-rolling-202303170317 or later
set system sflow interface eth0
set system sflow interface eth1
set system sflow interface eth2
set system sflow polling 30
set system sflow sampling-rate 1000
set system sflow server 10.0.0.30 port 6343
The above commands configure sFlow export in the VyOS CLI using the embedded Host sFlow agent.
docker run --name sflow-rt -p 8008:8008 -p 6343:6343/udp -d sflow/prometheus
A quick way to experiment with sFlow is to run the pre-built sflow/prometheus image Continue reading

VyOS

VyOS is an open source router operating system based on Linux. This article discusses how to improve network traffic visibility on VyOS based routers using the open source Host sFlow agent.

VyOS claims sFlow support, so why is it necessary to install an alternative sFlow agent? The following experiment demonstrates that there are significant issues with the VyOS sFlow implementation.

vyos@vyos:~$ show version
Version: VyOS 1.4-rolling-202301260317
Release train: current

Built by: [email protected]
Built on: Thu 26 Jan 2023 03:17 UTC
Build UUID: a95385b7-12f9-438d-b49c-b91f47ea7ab7
Build commit ID: d5ea780295ef8e

Architecture: x86_64
Boot via: installed image
System type: KVM guest

Hardware vendor: innotek GmbH
Hardware model: VirtualBox
Hardware S/N: 0
Hardware UUID: 6988d219-49a6-0a4a-9413-756b0395a73d

Copyright: VyOS maintainers and contributors
Install a recent version of VyOS under VirtualBox and configure routing between two Linux virtual machines connected to eth1 and eth2 on the router. Out of band management is configured on eth0.
set system flow-accounting disable-imt
set system flow-accounting sflow agent-address 10.0.0.50
set system flow-accounting sflow sampling-rate 1000
set system flow-accounting sflow server 10.0.0.30 port 6343
set system flow-accounting interface eth0
set system flow-accounting interface eth1
set system flow-accounting interface eth2
The above commands configure sFlow monitoring Continue reading

Real-time flow analytics with Containerlab templates

The GitHub sflow-rt/containerlab project contains example network topologies for the Containerlab network emulation tool that demonstrate real-time streaming telemetry in realistic data center topologies and network configurations. The examples use the same FRRouting (FRR) engine that is part of SONiC, NVIDIA Cumulus Linux, and DENT. Containerlab can be used to experiment before deploying solutions into production. Examples include: tracing ECMP flows in leaf and spine topologies, EVPN visibility, and automated DDoS mitigation using BGP Flowspec and RTBH controls.

This article describes an experiment with Containerlab's advanced Generated topologies capability, taking the 3 stage Clos topology shown above and creating a template that can be used to generate topologies with any number of leaf and spine switches.

The clos3.yml topology file specifies the 2 leaf 2 spine topology shown above:

name: clos3
mgmt:
network: fixedips
ipv4_subnet: 172.100.100.0/24
ipv6_subnet: 2001:172:100:100::/80

topology:
defaults:
env:
COLLECTOR: 172.100.100.8
nodes:
leaf1:
kind: linux
image: sflow/clab-frr
mgmt_ipv4: 172.100.100.2
mgmt_ipv6: 2001:172:100:100::2
env:
LOCAL_AS: 65001
NEIGHBORS: eth1 eth2
HOSTPORT: eth3
HOSTNET: "172.16.1.1/24"
HOSTNET6: "2001:172:16:1::1/64"
exec:
- touch /tmp/initialized
leaf2:
kind: linux
image: sflow/clab-frr
mgmt_ipv4: 172.100.100.3
mgmt_ipv6: 2001:172:100:100::3
env:
LOCAL_AS: 65002
NEIGHBORS: Continue reading

IPv6 flow analytics with Containerlab

CONTAINERlab is a Docker orchestration tool for creating virtual network topologies. The sflow-rt/containerlab project contains a number of topologies demonstrating industry standard streaming sFlow telemetry with realistic data center topologies. This article extends the examples in Real-time telemetry from a 5 stage Clos fabric and Real-time EVPN fabric visibility to demonstrate visibility into IPv6 traffic flows.

docker run --rm -it --privileged --network host --pid="host" \
-v /var/run/docker.sock:/var/run/docker.sock -v /run/netns:/run/netns \
-v $(pwd):$(pwd) -w $(pwd) \
ghcr.io/srl-labs/clab bash

Run the above command to start Containerlab if you already have Docker installed. Otherwise, Installation provides detailed instructions for a variety of platforms.

curl -O https://raw.githubusercontent.com/sflow-rt/containerlab/master/clos5.yml

Download the topology file for the 5 stage Clos fabric shown above.

containerlab deploy -t clos5.yml

Finally, deploy the topology.

The screen capture shows a real-time view of traffic flowing across the network during an iperf3 test. Click on the sFlow-RT Apps menu and select the browse-flows application, or click here for a direct link to a chart with the settings shown above.
docker exec -it clab-clos5-h1 iperf3 -c 2001:172:16:4::2

Each of the hosts in the network has an iperf3 server, so running the above command will test bandwidth between Continue reading

SC22 SCinet network monitoring

The data shown in the chart was gathered from The International Conference for High Performance Computing, Networking, Storage, and Analysis (SC22) being held this week in Dallas. The conference network, SCinet, is described as the fastest and most powerful network on Earth, connecting the SC community to the world. The chart provides an up to the second view of overall SCinet traffic, the lower chart showing total traffic hitting a sustained 8Tbps.
The poster shows the topology of the SCinet network. Monitoring flow data from 5,852 switch/router ports with 162Tbps total bandwith with sub-second latency is required to construct the charts.
The chart was generated using industry standard streaming sFlow telemetry from switches and routers in the SCinet network. An instance of the sFlow-RT real-time analytics engine computes the flow metrics shown in the charts.
Most of the load was due to large 400Gbit/s, 200Gbit/s and 100Gbit/s flows that were part of the Network Research Exhibition. The chart above shows that 10 large flows are responsible for 1.5Tbps of traffic.
Scientific network tags (scitags) describes how IPv6 flowlabels allow network flow analytics to identify network traffic associated with bulk scientific data transfers.
RDMA network visibility shows how bulk Continue reading

RDMA network visibility

The Remote Direct Memory Access (RDMA) data shown in the chart was gathered from The International Conference for High Performance Computing, Networking, Storage, and Analysis (SC22) being held this week in Dallas. The conference network, SCinet, is described as the fastest and most powerful network on Earth, connecting the SC community to the world.
Resilient Distributed Processing and Reconfigurable Networks is one of the demonstrations using SCinet - Location: Booth 2847 (StarLight). Planned SC22 focus is on RDMA enabled data movement and dynamic network control.
  1. RDMA Tbps performance over global distance for timely Terabyte bulk data transfers (goal << 1 min Tbyte transfer on N by 400G network).
  2. Dynamic shifting of processing and network resources from on location/path/system to another (in response to demand and availability).
The real-time chart at the top of this page shows an up to the second view of RDMA traffic (broken out by source, destination, and RDMA operation).
The chart was generated using industry standard streaming sFlow telemetry from switches and routers in the SCinet network. An instance of the sFlow-RT analytics engine computes the RDMA flow metrics shown in the chart. RESTflow describes how sFlow disaggregates the traditional NetFlow / IPFIX analytics pipeline Continue reading

Scientific network tags (scitags)

The data shown in the chart was gathered from The International Conference for High Performance Computing, Networking, Storage, and Analysis (SC22) being held this week in Dallas. The conference network, SCinet, is described as the fastest and most powerful network on Earth, connecting the SC community to the world. The chart shows data generated as part of the Packet Marking for Networked Scientific Workflows demonstration using SCinet - Booth 2847 (StarLight).

Scientific network tags (scitags) is an initiative promoting identification of the science domains and their high-level activities at the network level. Participants include, dCacheESnet, GÉANT, Internet2, Jisc, NORDUnet, OFTS, OSG, RNP, RUCIO, StarLight, XRootD.

This article will demonstrate how industry standard sFlow telemetry streaming from switches and routers can be used to report on science domain activity in real-time using the sFlow-RT analytics engine.

The scitags initiative makes use of the IPv6 packet header to mark traffic. Experiment and activity identifiers are encoded in the IPv6 Flow label field. Identifiers are published in an online registry in the form of a JSON document, https://www.scitags.org/api.json.

One might expect IPFIX / NetFlow to be a Continue reading

Low latency flow analytics


Real-time analytics on network flow data with Apache Pinot describes LinkedIn's flow ingestion and analytics pipeline for sFlow and IPFIX exports from network devices. The solution uses Apache Kafka message queues to connect LinkedIn's InFlow flow analyzer with the Apache Pinot datastore to support low latency queries. The article describes the scale of the monitoring system, InFlow receives 50k flows per second from over 100 different network devices on the LinkedIn backbone and edge devices and states InFlow requires storage of tens of TBs of data with a retention of 30 days. The article concludes, Following the successful onboarding of flow data to a real-time table on Pinot, freshness of data improved from 15 mins to 1 minute and query latencies were reduced by as much as 95%.
The sFlow-RT real-time analytics engine provides a faster, simpler, more scaleable, alternative for flow monitoring. sFlow-RT  radically simplifies the measurement pipeline, combining flow collection, enrichment, and analytics in a single programmable stage. Removing pipeline stages improves data freshness — flow measurements represent an up to the second view of traffic flowing through the monitored network devices. The improvement from minute to sub-second data freshness enhances automation use cases such as automated DDoS Continue reading

DDoS Sonification

Sonification presents data as sounds instead of visual charts. One of the best known examples of sonification is the representation of radiation level as a click rate in a Geiger counter. This article describes ddos-sonify, an experiment to see if sound can be usefully employed to represent information about Distributed Denial of Service (DDoS) attacks. The DDoS attacks and BGP Flowspec responses testbed was used to create the video demonstration at the top of this page in which a series of simulated DDoS attacks are detected and mitigated. Play the video to hear the results.

The software uses the Tone.js library to control Web Audio sound generation functionality in a web browser.

var voices = {};
var loop;
var loopInterval = '4n';
$('#sonify').click(function() {
if($(this).prop("checked")) {
voices.synth = new Tone.PolySynth(Tone.Synth).toDestination();
voices.metal = new Tone.PolySynth(Tone.MetalSynth).toDestination();
voices.pluck = new Tone.PolySynth(Tone.PluckSynth).toDestination();
voices.membrane = new Tone.PolySynth(Tone.MembraneSynth).toDestination();
voices.am = new Tone.PolySynth(Tone.AMSynth).toDestination();
voices.fm = new Tone.PolySynth(Tone.FMSynth).toDestination();
voices.duo = new Tone.PolySynth(Tone.DuoSynth).toDestination();
Tone.Transport.bpm.value=80;
loop = new Tone.Loop((now) => {
sonify(now);
},loopInterval).start(0);
Continue reading