Extended Architecture of the Industrial Environment

This section describes the extended architecture of the Webitel production environment designed for ~1,000,000 calls and ~200,000 chats per day.

1. General Architecture Diagram

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 a load of 400–500 simultaneous calls (~1 million calls per day) and 200,000+ chats per day, you need to prepare 7 virtual machines (items 1–6 in the table below).

Deployment requirements:

Install only the operating system and keep Internet access enabled to download and install additional software.
After installation is complete, Internet access may be disabled on all virtual machines.
Virtual machines 1–6 must operate within the same VLAN, with no port filtering (allow all traffic).
Developers must be provided with SSH access using root privileges for the duration of installation and testing.
The reservation should be provided by the capacity of virtual machines.

4. Server Specification

Object	Software	Resources (min)	Connectivity	Description
Webitel Server	Debian 12 Linux 64bit - basic server installation with SSH connection; Additionally, we will install: Nginx; SSL; Webitel Services	4 vCPU > 2,4 GHz (Haswell generation or newer), No more than 2 virtual cores per 1 physical core 8Gb RAM 80 GB, 2000 IOPS 2 network interfaces >= 1 GbE	in-out: 80/tcp, 443/tcp	SSL certificates with a trusted CA are required to provide a secure connection via HTTPS protocol and telephony in a browser. Scaling is possible.
PostgreSQL	Debian 12 Linux 64bit - basic server installation with SSH connection; Additionally, we will install: Linux; PostgreSQL 15; Grafana	8 vCPU, > 2,6 GHz (Haswell generation or newer), No more than 2 virtual cores per 1 physical core 16Gb RAM 80 GB, 2000 IOPS 500+ GB, 5000 IOPS 1 network interface >= 1 GbE		PostgreSQL database server with configured Streaming Replication.
MQ & Storage Server	Debian 12 Linux 64bit - basic server installation with SSH connection; Additionally, we will install: Linux; Redis Server; Consul; RabbitMQ; Webitel Storage	4 vCPU, > 2,6 GHz (Haswell generation or newer), No more than 2 virtual cores per 1 physical core 8Gb RAM 120 GB, 2000 IOPS 1 network interface >= 1 GbE		Application registration server, messaging service, and call recording storage. The call records are stored in S3 storage.
OpenSIPS & rtpengine	Debian 12 Linux 64bit - basic server installation with SSH connection; Additionally, we will install: OpenSIPS 3.4, Rtpengine;	8 vCPU > 2,6 GHz (Haswell generation or newer), No more than 2 virtual cores per 1 physical core 16Gb RAM 60 GB, 2000 IOPS 2 network interfaces >= 1 GbE	5060/tcp, 5060/udp, 5061/tcp in-out: 10000-50000/udp	Telephony server. Scaling is possible.
FreeSWITCH	Debian 12 Linux 64bit - basic server installation with SSH connection; Additionally, we will install: FreeSWITCH; Webitel FlowManager;	8 vCPU, > 2,6 GHz (Haswell generation or newer), No more than 2 virtual cores per 1 physical core 16Gb RAM 120 GB, 2000 IOPS 1 network interface >= 1 GbE		Server for building voice applications. When the load increases, it is necessary to duplicate the server. Scaling is possible.
Homer & Grafana	Debian 12 Linux 64bit - basic server installation with SSH connection; Additionally, we will install: Homer + PostgreSQL, Grafana;	4 vCPU, > 2,6 GHz (Haswell generation or newer), No more than 2 virtual cores per 1 physical core 8Gb RAM 200 GB, 2000 IOPS 1 network interfaces >= 1 GbE		Grafana for analytics. Collection of logs and call logs.
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
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
External Data Services				Integrations with external systems
10. 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'.