Quy tac dat ten Wi-Fi SSID - Ky tu cho phep va gioi han do dai
SSID (ten mang Wi-Fi) co gioi han toi da 32 byte. Khi su dung UTF-8, mot ky tu tieng Viet co dau co the chiem 2-3 byte, nen so ky tu thuc te su dung duoc it hon nhieu so voi tieng Anh. Cac SSID tai quan ca phe va san bay deu la ket qua thiet ke nham "de tim, de nho va an toan" trong gioi han nay.
Gioi han ky thuat cua SSID
| Hang muc | Gioi han | Can cu |
|---|---|---|
| Do dai toi da | 32 byte | Tieu chuan IEEE 802.11 |
| Do dai toi thieu | 1 byte | Khong cho phep chuoi rong |
| Ky tu cho phep | Bat ky chuoi byte nao | Tieu chuan khong gioi han |
| Ma hoa | UTF-8 (khuyen nghi) | Wi-Fi Alliance khuyen nghi |
| Phan biet hoa/thuong | Co | "MyWiFi" va "mywifi" la hai SSID khac nhau |
Diem quan trong la gioi han la "32 byte" chu khong phai "32 ky tu". Ky tu ASCII (chu cai, so) moi ky tu chiem 1 byte nen dung duoc 32 ky tu. Nhung tieng Nhat voi UTF-8 moi ky tu chiem 3 byte, chi dung duoc toi da 10 ky tu. Day la vi du dien hinh ve su khac biet giua so ky tu va so byte trong thuc te.
So ky tu SSID theo loai ky tu
| Loai ky tu | Byte/ky tu (UTF-8) | So ky tu trong 32 byte | Vi du |
|---|---|---|---|
| ASCII (chu va so) | 1 byte | 32 ky tu | MyHomeNetwork-5GHz-2F |
| Tieng Viet co dau | 2-3 byte | 10-16 ky tu | Wifi-nha-toi |
| Tieng Nhat (kanji) | 3 byte | 10 ky tu | 田中家無線 |
| Emoji | 4 byte | 8 ky tu | Mot so thiet bi khong ho tro |
| Ket hop (ASCII + tieng Viet) | 1-3 byte | Tuy truong hop | Cafe-HaNoi (10 byte) |
Thuc hanh tot nhat khi dat ten SSID
| Muc dich | Mau khuyen nghi | Vi du | Ly do |
|---|---|---|---|
| Gia dinh | Chu va so de nhan biet | Nguyen-Home-5G | Phan biet voi hang xom |
| Van phong | Ten cong ty + tang + bang tan | ACME-3F-5GHz | De quan ly |
| Quan ca phe/cua hang | Ten cua hang + Free/Guest | CafeBlue-Free | Khach hang de tim |
| Su kien | Ten su kien + nam | TechConf2026 | Phu hop su dung tam thoi |
Thong tin khong nen co trong SSID
Tu goc do bao mat, nhung thong tin sau khong nen xuat hien trong SSID.
| Mau khong nen | Vi du | Rui ro |
|---|---|---|
| Ho ten + so phong | Nguyen-301 | Co the lo dia chi |
| Ten model router | TP-Link-AX6000 | Bi loi dung de tim lo hong |
| Goi y mat khau | pass-is-birthday | Cung cap manh moi doan mat khau |
| Ten nha mang | VNPT-Nguyen | Suy doan thong tin hop dong |
Nhu da trinh bay trong do dai mat khau va bao mat, bao mat mang bat dau tu cach dat ten. SSID co the quet duoc tu ben ngoai toa nha, nen khong nen chua thong tin nhan dang ca nhan.
The gioi SSID thu vi
SSID cung la khong gian bieu dat tu do trong 32 byte. Duoi day la nhung SSID thu vi duoc phat hien tren khap the gioi.
| SSID | So byte | Y nghia |
|---|---|---|
| Pretty Fly for a Wi-Fi | 22 | Nhai ten bai hat cua The Offspring |
| FBI Surveillance Van | 20 | Tro dua voi hang xom |
| Get Your Own WiFi | 18 | Thong diep chong xai chua |
| It Burns When IP | 17 | Choi chu IT (IP address) |
| Tell My WiFi Love Her | 22 | Nhai "Tell My Wife I Love Her" |
Gui gam su hai huoc va thong diep trong gioi han 32 byte. Giong nhu gioi han 140 ky tu cua X (Twitter cu) da tao ra van hoa doc dao, gioi han 32 byte cua SSID cung sinh ra mot nen van hoa bieu dat nho.
Chien luoc dat ten SSID cho 5 GHz va 2.4 GHz
Router bang tan kep cho phep dat SSID khac nhau cho hai bang tan hoac dung chung mot SSID.
Khi dat rieng, dung hau to nhu "Home-5G", "Home-2G" de phan biet. Khi dung chung, tinh nang band steering cua router se tu dong ket noi bang tan tot nhat. Muon giam cong quan ly thi dung chung SSID, muon chon bang tan thu cong thi dat rieng.
Du chon cach nao, can tinh den so byte cua hau to ("-5G" chiem 3 byte). Gioi han 32 byte can bao gom ca viec phan biet bang tan trong thiet ke.
Sach ve Wi-Fi va mang co the tim tren Amazon.