VoIP Server VPS: Asterisk Va FreePBX Self-Hosted

Twilio luu CDR, audio recording va metadata trong AWS US East. Voi doanh nghiep o jurisdiction khac, day la rui ro phap ly nghiem trong. Hon nua, chi phi Twilio tinh per-minute - chi phi se phi mai cho cong ty quy mo trung binh.

Bon nhom doanh nghiep huong loi nhat tu VoIP self-hosted:

• Cong ty luat: Cuoc goi voi khach hang co privilege bao mat tuyet doi. Audio recording phai trong jurisdiction kiem soat.
• Bao chi dieu tra: Cuoc goi voi nguon tin can E2EE va khong luu CDR ben thu ba.
• Call center quy mo trung: 50+ agent tao 10,000+ cuoc goi/ngay. Chi phi Twilio se vuot $5000/thang. VoIP self-hosted chi can VPS Pro $24.99/thang + SIP trunk thuong khong qua $200/thang.
• Cong ty offshore: Khach hang quoc te muon goi qua so noi dia o nhieu nuoc. Asterisk + DID provider linh hoat hon cau hinh cua Twilio.

VPS Pro AnubizHost voi 4GB RAM du cho Asterisk phuc vu 50-100 cuoc goi dong thoi (concurrent call). Bang thong 5-10 Mbps cho moi cuoc goi G.711, hoac 100 Kbps neu dung Opus codec.

FreePBX la giao dien web cho Asterisk, giup quan ly de dang. Cai dat tren Debian 12:

apt update && apt install -y wget gnupg
wget https://github.com/FreePBX/freepbx/archive/refs/tags/release/16.0.tar.gz
# Hoac dung distro chinh thuc voi installer:
wget https://downloads.freepbxdistro.org/ISO/SNG7-FPBX-64bit-2302-1.iso
# Tot hon: cai bang script chinh thuc tren Debian
apt install -y asterisk asterisk-modules
# Cai web UI FreePBX:
wget https://github.com/FreePBX/freepbx/raw/release/16.0/install.sh
bash install.sh

Sau khi cai dat, truy cap web UI tai http://vps-ip/admin. Buoc bao mat dau tien:

• Doi password admin mac dinh ngay lap tuc.
• Cau hinh HTTPS: Lay cert Lets Encrypt, su dung Caddy reverse proxy.
• Han che IP truy cap web UI: Chi tu IP cua admin hoac qua VPN noi bo.

Tao extension cho user trong FreePBX UI: Applications -> Extensions -> Add Extension -> SIP/PJSIP. Moi user nhan SIP credentials de cau hinh trong app (Zoiper, Linphone, hardware phone Yealink/Polycom).

Mua SIP trunk tu Twilio Programmable Voice, VoIP.ms, hoac Anveo. Cau hinh trunk trong FreePBX: Connectivity -> Trunks -> Add Trunk -> SIP (chan SIP). Nhap thong tin tu provider.

Cau hinh inbound route (cuoc goi den so ban mua) va outbound route (cuoc goi tu user qua trunk). Test bang cach goi tu phone den so DID va kiem tra audio.

VoIP server la muc tieu hap dan cho hacker tan cong toll fraud. Bao mat la uu tien hang dau.

1. Bat SRTP cho ma hoa audio: Mac dinh RTP truyen audio plaintext. SRTP ma hoa packet - khong nghe trom duoc. Trong FreePBX, Settings -> SIP Settings -> Secure SIP, bat Encryption: yes.

2. Bat TLS cho SIP signaling: Cong 5061 voi cert, thay vi 5060 plaintext. Tu duo SIP signaling khong de bi nghe trom.

3. Fail2ban Asterisk: Mac dinh AnubizHost VPS co fail2ban. Kich hoat jail Asterisk de tu chan IP brute force:

# /etc/fail2ban/jail.d/asterisk.conf
[asterisk]
enabled = true
filter = asterisk
logpath = /var/log/asterisk/messages
maxretry = 5
findtime = 600
bantime = 86400

4. Han che outbound destination: Trong FreePBX Outbound Routes, chi cho phep goi den cac quoc gia ban thuc su can. Tat ca dia chi premium-rate (00800, +900) phai bi chan tuyet doi.

5. Cap PIN cho long-distance call: User phai nhap PIN truoc khi goi quoc te. Han che thiet hai neu account bi compromise.

6. Monitoring CDR bat thuong: Cron 15 phut kiem tra CDR. Alert Telegram khi thay >50 cuoc goi/15 phut tu mot extension hoac >5 cuoc goi quoc te trong 1 gio.

Voi 6 lop tren, Asterisk PBX cua ban tren AnubizHost VPS Iceland tro thanh he thong VoIP doanh nghiep an toan, kinh te va co bao mat phap ly - tot hon cac dich vu thuong mai ve ca quyen rieng tu lan chi phi van hanh dai han.