Webitel: Documentation
Webitel: Documentation
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Basic Architecture of the Industrial Environment

This section describes the basic architecture of the Webitel production environment designed for approximately ~400,000 calls and ~100,000 chats per day.

1. General Architecture Diagram

Webitel Basic.png

2. Deployment Environment Requirements

The Webitel architecture is designed to operate in environments with isolated and guaranteed resources. Using budget VPS/VDS (Virtual Private/Dedicated Server) instances with shared CPU time is not recommended due to the risks of “noisy neighbors” and high network latency, which is critical for the quality of VoIP components (FreeSWITCH, RTP, OpenSIPS).

Supported platforms include:

  • On-Premise (Local servers):

    • Physical servers (Bare Metal);

    • Enterprise hypervisors (VMware, KVM, Xen, Proxmox VE).

  • Cloud Providers:

    • AWS (Amazon EC2);

    • Google Cloud (Compute Engine);

    • Microsoft Azure (Virtual Machines);

    • DigitalOcean (Droplets);

    • Hetzner (Cloud / Dedicated).

IMPORTANT! When choosing cloud provider plans (especially DigitalOcean and Hetzner), it is strongly recommended to select virtual machines in the following categories:

  • Dedicated vCPU, or

  • Compute-Optimized,

for components responsible for media and voice processing.

3. Description of the General Infrastructure

For an industrial environment with an average load of up to 400,000 calls per day (250–350 simultaneous with call recording) and about 100,000 chats per day, it is necessary to prepare 3 virtual machines (items 1–3 in the table below).

Deployment requirements:

  • Install only the operating system, and keep Internet access enabled to download and install all additional software.

  • After the installation is complete, Internet access on the virtual machines may be disabled.

  • Developers must be provided with SSH access using root privileges for the duration of installation and testing.

  • Virtual machines 1–3 must operate within the same VLAN, with no traffic filtering (allow all ports).

  • The reservation should be provided by the capacity of virtual machines.

4. Server Specification

Object

Software

Resources (min)

Connectivity

Description

  1. Telephony application server

Debian 12 Linux 64bit — basic server installation with SSH connection;

Additionally, we will install:

OpenSIPS 3.4; rtpengine; nginx; SSL; 

  • 4 vCPU > 2,6 GHz (Haswell generation or newer), No more than 2 virtual cores per 1 physical core

  • 8Gb RAM

  • 60 GB, 1000 IOPS, 

  • 1 network interface >= 1 GbE

in-out: 80/tcp, 443/tcp, 5060/tcp, 5060/udp

in-out: 10000-50000/udp

Telephony server. SSL certificates with a trusted CA are required to provide a secure connection via HTTPS protocol and telephony in a browser.

  1. Database Server

Debian 12 Linux 64bit — basic server installation with SSH connection;

Additionally, we will install:

Linux; PostgreSQL 15; Grafana; Consul; RabbitMQ; 

  • 8 vCPU, > 2,8 GHz (Haswell generation or newer), No more than 2 virtual cores per 1 physical core

  • 16Gb RAM

  • 60 GB, 1000 IOPS

  • 250 GB, 2000 IOPS

  • 1 network interface >= 1 GbE



  • Database.

  • Microservice registration service.

  • Messaging bus.

We recommend duplicating the server to configure Streaming Replica.

  1. Application Server

Debian 12 Linux 64bit — basic server installation with SSH connection;

Additionally, we will install:

FreeSWITCH 10; Webitel FlowManager; Webitel App; Webitel API GW; Storage; CallCenter; Engine; Messages

  • 8 vCPU, > 2,6 GHz (Haswell generation or newer), No more than 2 virtual cores per 1 physical core

  • 16Gb RAM

  • 80 GB, 1000 IOPS

  • 1 TB, 200 IOPS, <10 мс (if S3 is not used)

  • 1 network interface >= 1 GbE


  • Applications server.

  • Server for creating voice menus.

  • Storage of conversation recordings.

  1. External Data Services




Interaction with external systems runs via HTTP REST.

  1. Team

Microsoft Windows 11 / Linux 64bit

Google Chrome / Microsoft Edge (the latest or previous version)

  • 4 vCPU

  • 8Gb RAM

Connection to the IS not less than 2 Mb/s per user, with delays of no more than 15-20 ms.

Employees’ workplace

  1. Hardware SIP Phone



Connection to the IS not less than 5 Mb/s per device, with delays of no more than 15-20 ms.

in-out: 5060/udp, 10000-20000/udp

Hardware phone with SIP 2.0 protocol support

  1. PSTN




Public Switched Telephone Network is a general subscriber communication network, the access to which is provided by telephone sets, PBX, and data transmission equipment.

5. Network Parameter Requirements


Connection speed

Delay (Ping)

Jitter

Packet Loss

WebRTC

  • For audio calls: at least 100–300 Kbps.

  • For video calls (standard quality): at least 1–2 Mbps.

  • For high-quality video (HD or Full HD): at least 2–4 Mbps.

  • For conferences or streams (4K video): 8–25 Mbps is recommended.

  • Optimal delay for WebRTC should be less than 50 ms.

  • Acceptable delay: 50-100 ms.

  • If delay exceeds 150 ms, noticeable delays during calls or video may occur.

  • Optimal jitter should be less than 30 ms. Jitter refers to variations in packet delay, and high jitter can significantly degrade audio or video quality.

  • Jitter over 50 ms can cause distortion or delays in audio/video.

  • Optimal packet loss for WebRTC: less than 1%.

  • Loss of up to 2-3% may be acceptable for audio, but it will degrade video quality.

  • Loss above 5% will significantly impair communication, causing noticeable interruptions, artifacts, or video 'freezes'.