喺香港，上網慢或者斷線係令人最頭痛嘅事之一。無論你係 WFH 開緊 Zoom、打機打到一半 lag 死、定係煲劇不斷 buffer，呢篇指南都會一步步教你點樣自己排除故障，搵出問題根源，甚至喺唔需要打電話俾 ISP 嘅情況下解決問題。
In Hong Kong, slow or unreliable internet is one of the most frustrating everyday problems. Whether you are on a Zoom call for work, lagging in the middle of a game, or endlessly buffering a show, this guide walks you through troubleshooting step by step — helping you identify the root cause and often fix it without needing to call your ISP.
第一步：基本檢查 Step 1: Basic Checks
重啟路由器同 ONU Restart Your Router & ONU
呢個聽落好老土，但係確實有效 — 大部分網絡問題都可以靠重啟解決。正確做法：先關閉路由器電源，再關閉 ONU（光纖終端機，通常係 ISP 安裝嘅白色小盒子），等待 30 秒，然後先開 ONU，等佢所有燈穩定（大約 1-2 分鐘），再開路由器。呢個過程可以清除路由器嘅暫存記憶，解決好多臨時性嘅連線問題。
It sounds cliché, but it genuinely works — most network issues can be resolved with a reboot. The proper method: power off the router first, then the ONU (the small white box installed by your ISP), wait 30 seconds, power on the ONU first and wait until all lights stabilize (about 1-2 minutes), then power on the router. This clears the router's cached memory and resolves many transient connectivity issues.
檢查實體連接 Check Physical Connections
檢查所有網線（LAN cable）有冇鬆脫或者損壞。特別留意 ONU 同路由器之間嘅網線、以及牆身光纖插座嘅連接。如果網線用咗好耐，可能已經氧化或者折損，換一條新嘅 Cat 5e 或 Cat 6 網線可能即刻解決問題。另外檢查 ONU 上嘅光纖指示燈（通常標示 PON 或 OPTICAL）— 如果係紅色或者熄咗，代表光纖線路有問題，需要聯絡 ISP。
Inspect all Ethernet cables for loose or damaged connections. Pay special attention to the cable between the ONU and router, and the fibre wall socket. Old cables may be oxidized or crimped — replacing with a new Cat 5e or Cat 6 cable may solve the problem instantly. Also check the fibre indicator on your ONU (usually labeled PON or OPTICAL) — if it is red or off, there is a fibre line issue requiring ISP assistance.
If the ONU lights are normal (green) but the router is unresponsive, the issue is likely the router. If ONU lights are abnormal (red/flashing), the problem lies with the ISP's line.
第二步：WiFi vs 有線測試 Step 2: WiFi vs Wired Testing
分辨問題係出喺 WiFi 定係寬頻本身非常重要。用一條網線直接將電腦連接到路由器（或者 ONU），然後進行速度測試。如果有線速度正常但 WiFi 慢，咁問題出喺無線環節；如果有線都慢，問題就出喺寬頻線路或者 ISP 端。
Distinguishing between a WiFi problem and a broadband problem is crucial. Connect a computer directly to the router (or ONU) with an Ethernet cable and run a speed test. If wired speed is fine but WiFi is slow, the issue is wireless; if wired speed is also slow, the problem lies with the broadband line or ISP.
For wired testing, try connecting directly to the ONU (bypassing the router) to rule out router issues. If direct-to-ONU speed is fine but slows through the router, your router may need replacing or resetting.
第三步：正確進行速度測試 Step 3: Speed Test Methodology
好多人測速嘅方法唔啱，導致結果唔準確。以下係正確嘅測速步驟：
1. 使用可靠嘅測速工具 — 推薦使用 Speedtest.net（by Ookla）、Fast.com（by Netflix）或 OFCA 嘅官方寬頻表現測試。選擇香港本地嘅伺服器進行測試。
2. 測試環境要正確 — 關閉所有其他正在使用網絡嘅應用程式同裝置（串流、下載、雲端同步等）。用有線連接（唔好用 WiFi）進行測試。
3. 多次測試取平均值 — 做至少 3 次測試，取平均值。同一時間、唔同時間各做幾次，觀察有冇差異。
4. 記錄結果 — 截圖或記低每次嘅下載速度、上傳速度同延遲。如果需要向 ISP 投訴，呢啲就係你嘅證據。
Many people test their speed incorrectly, leading to inaccurate results. Here is the proper approach: 1) Use reliable tools like Speedtest.net (Ookla), Fast.com (Netflix), or OFCA's official broadband performance test, selecting a Hong Kong server. 2) Close all other network-using apps and devices (streaming, downloads, cloud sync). Test over a wired connection, not WiFi. 3) Run at least 3 tests and average the results. Test at different times of day to spot patterns. 4) Record all results with screenshots — download speed, upload speed, and latency. These serve as evidence if you need to file a complaint.
第四步：繁忙時段擠塞 Step 4: Peak Hour Congestion
如果你發現上網慢嘅情況主要出現喺晚上 7 點到 11 點，呢個好大機會係繁忙時段擠塞（peak hour congestion）。因為同一棟大廈甚至同一區嘅住戶都喺同一時間上網煲劇、打機，共享嘅頻寬會變得擠迫。
呢個問題可能出喺幾個層面：大廈內部嘅共享線路（特別係 FTTB 嘅大廈）、ISP 到你大廈嘅回程線路（backhaul）、或者 ISP 嘅國際出口頻寬。如果繁忙時段速度持續只有計劃速度嘅一半甚至更低，你有理由向 ISP 投訴或考慮轉台。
If your internet slows down primarily between 7 PM and 11 PM, it is very likely peak hour congestion. Residents in the same building or area are all streaming and gaming simultaneously, straining the shared bandwidth. The bottleneck could be at several levels: shared internal building wiring (especially in FTTB buildings), the ISP's backhaul to your building, or the ISP's international bandwidth. If speeds consistently drop to half your plan's speed or lower during peak hours, you have grounds to complain to your ISP or consider switching.
第五步：WiFi 優化（香港屋企篇）Step 5: WiFi Optimization for HK Flats
路由器擺位 Router Placement
香港嘅住宅面積細，但間隔多（廳、房、廚、廁），加上牆身可能用咗鋼筋混凝土，WiFi 信號穿牆後會大幅衰減。最佳做法：
-- 將路由器放喺屋企嘅中央位置，盡量減少信號需要穿過嘅牆數量。
-- 放高一啲，例如放喺櫃頂或者書架上面，唔好放喺地下或者櫃入面。
-- 遠離干擾源，包括微波爐、無線電話座機、藍牙裝置、魚缸（水會吸收 WiFi 信號）。
-- 唔好放入電視櫃，封閉空間會阻擋信號同令路由器過熱。
Hong Kong flats are small but heavily partitioned (living room, bedrooms, kitchen, bathroom), often with reinforced concrete walls that heavily attenuate WiFi signals. Best practices: Place the router centrally to minimize the number of walls signals must penetrate. Elevate it on a shelf or cabinet top — never on the floor or inside a cabinet. Keep it away from interference sources like microwaves, cordless phones, Bluetooth devices, and fish tanks (water absorbs WiFi signals). Never enclose it inside a TV cabinet, which blocks signals and causes overheating.
鄰居干擾與頻道設定 Channel Interference from Neighbors
香港住宅密度極高，你嘅路由器可能被十幾個鄰居嘅 WiFi 信號包圍，大家爭用相同嘅頻道就會造成干擾，令速度下降。解決方法：
-- 使用 WiFi 分析工具（如 WiFi Analyzer app）掃描附近嘅 WiFi 網絡，搵出最少人用嘅頻道。
-- 2.4GHz 頻段：選擇頻道 1、6 或 11（呢三個頻道互不重疊）。
-- 5GHz 頻段：頻道數量多、干擾少，如果路由器支援就盡量用 5GHz。
-- 唔好用「自動頻道」：雖然方便，但路由器嘅自動選擇唔一定最佳，特別喺高密度環境。手動設定你測試過最好嘅頻道。
Hong Kong's extreme residential density means your router may be surrounded by a dozen neighbors' WiFi networks, all competing for the same channels and causing interference. Solutions: Use a WiFi analyzer app to scan nearby networks and find the least congested channel. For 2.4GHz, choose channels 1, 6, or 11 (these are the only non-overlapping channels). For 5GHz, there are many more channels with less interference — use 5GHz whenever possible. Avoid "auto channel" — while convenient, the router's automatic selection is often suboptimal in dense environments. Manually set the best channel you have tested.
第六步：DNS 優化 Step 6: DNS Optimization
ISP 預設嘅 DNS 伺服器有時候會比較慢或者唔穩定，影響開網頁嘅速度。你可以手動更改 DNS 設定嚟改善體驗：
Cloudflare: 1.1.1.1（主）/ 1.0.0.1（備）— 全球最快之一，注重私隱
Google: 8.8.8.8（主）/ 8.8.4.4（備）— 穩定可靠，全球通用
Quad9: 9.9.9.9（主）/ 149.112.112.112（備）— 自動阻擋惡意網站
你可以喺路由器嘅設定頁面更改 DNS，咁全屋裝置都會受惠。或者逐部裝置喺網絡設定入面更改。
You can change DNS in your router's settings page (benefiting all devices), or configure it on individual devices in their network settings.
Your ISP's default DNS servers can sometimes be slow or unreliable, affecting page load times. Switching to a public DNS service like Cloudflare (1.1.1.1), Google (8.8.8.8), or Quad9 (9.9.9.9) can noticeably improve web browsing speed. Change it in your router's admin panel so all connected devices benefit automatically.
第七步：檢查「爆 Port」問題 Step 7: Checking for Port Congestion
「爆 port」係香港人嘅俗語，指大廈嘅電訊機房端口被過多用戶佔用，導致頻寬不足。呢個情況常見於舊式大廈或者人口密集嘅公共屋邨。徵狀包括：速度持續遠低於合約速度、繁忙時段特別嚴重、而且唔係得你一個受影響（可以問下鄰居）。
如果你懷疑「爆 port」，可以採取以下步驟：
1. 記錄多日嘅速度測試結果，特別係繁忙時段同非繁忙時段嘅對比。
2. 打電話俾 ISP 客服，明確提出你懷疑係端口擠塞問題，要求佢哋檢查你大廈嘅端口使用情況。
3. 要求 ISP 升級大廈嘅設備或者增加端口容量。
4. 如果 ISP 唔處理，可以向 OFCA 投訴（見下文）。
5. 考慮轉用覆蓋你大廈嘅其他 ISP，佢哋可能有較充裕嘅端口資源。
"Port congestion" (爆 port) is a local Hong Kong term for when a building's telecom room has too many users on too few ports, resulting in insufficient bandwidth. It is common in older buildings and densely populated public housing estates. Symptoms include speeds consistently far below your plan, especially during peak hours, and affecting multiple residents (ask your neighbors). If suspected: 1) Document speed tests over several days, comparing peak vs off-peak. 2) Call your ISP and explicitly state you suspect port congestion, requesting they inspect the building's port utilization. 3) Request equipment upgrades or additional port capacity. 4) If unresolved, file an OFCA complaint. 5) Consider switching to another ISP that covers your building and may have more available capacity.
第八步：韌體更新 Step 8: Firmware Updates
路由器嘅韌體（firmware）係佢嘅「作業系統」。過期嘅韌體可能有安全漏洞、效能問題，甚至同某啲裝置唔兼容。定期更新韌體可以改善穩定性同速度。
更新方法：登入路由器管理頁面（通常係 192.168.1.1 或 192.168.0.1），搵到「韌體更新」或「Firmware Update」選項，檢查有冇新版本。大部分新款路由器支援自動更新，但記得開啟呢個功能。如果你用緊 ISP 提供嘅路由器，韌體更新通常由 ISP 遠端推送。
Your router's firmware is its operating system. Outdated firmware may contain security vulnerabilities, performance bugs, or device compatibility issues. Regular updates can improve both stability and speed. How to update: Log into your router's admin panel (usually 192.168.1.1 or 192.168.0.1), find "Firmware Update," and check for new versions. Most modern routers support automatic updates — make sure this feature is enabled. If using an ISP-provided router, firmware updates are usually pushed remotely by the ISP.
第九步：幾時應該打電話俾 ISP？ Step 9: When to Call Your ISP
如果你已經做晒以上所有步驟，問題仍然存在，就係時候聯絡 ISP 嘅技術支援。打電話之前準備好以下資訊，可以大幅加快處理速度：
-- 你嘅帳戶號碼同合約計劃
-- 速度測試截圖（包括日期、時間、測試結果）
-- 問題出現嘅時間規律（例如每晚 8-11 點特別慢）
-- 你已經做過嘅排除步驟（重啟、有線測試等）
-- ONU 指示燈嘅狀態
If you have completed all the above steps and the problem persists, it is time to contact your ISP's technical support. Before calling, prepare: your account number and plan details, speed test screenshots with dates and times, the pattern of when issues occur (e.g., slow every evening 8-11 PM), troubleshooting steps you have already taken (reboots, wired testing, etc.), and the status of your ONU indicator lights. Having this information ready significantly speeds up the support process.
Always note down the agent's name and reference/ticket number. If they promise to "follow up" with no result, the reference number lets you track progress. If the first agent cannot resolve it, request escalation to senior technical support.
第十步：向 OFCA 投訴 Step 10: Filing an OFCA Complaint
如果 ISP 嘅回應令你唔滿意，或者問題持續冇改善，你可以向通訊事務管理局（OFCA）投訴。OFCA 係香港嘅電訊監管機構，有權調查 ISP 嘅服務質素問題。
投訴途徑 Complaint Channels:
-- 網上投訴表格：OFCA 官方網站 (www.ofca.gov.hk)
-- 電話投訴熱線：186 006
-- 郵寄投訴
投訴時需要提供 Information Required:
-- 你嘅 ISP 名稱同帳戶資料
-- 問題詳細描述（包括日期、時間）
-- 你已同 ISP 溝通嘅記錄（日期、工單編號、結果）
-- 速度測試證據
If your ISP's response is unsatisfactory or the problem persists, you can escalate to OFCA (Office of the Communications Authority), Hong Kong's telecom regulator with authority to investigate ISP service quality issues. Complaint channels: online form at www.ofca.gov.hk, hotline 186 006, or postal mail. You will need: your ISP name and account details, detailed problem description with dates, records of your ISP communications (dates, reference numbers, outcomes), and speed test evidence.
第十一步：考慮轉台 Step 11: When to Switch Providers
如果以下情況持續出現，可能真係時候考慮轉台：
-- 速度長期達唔到合約承諾嘅一半，ISP 多次維修後仍未改善。
-- 經常無故斷線，影響工作同日常使用。
-- ISP 客服態度差，唔配合解決問題。
-- 合約即將到期，而其他 ISP 提供更好嘅價格或速度。
-- 你嘅大廈有新 ISP 鋪設光纖，提供 FTTH 而你而家用緊 FTTB。
Consider switching providers if: speeds consistently fall below half your plan's promise despite multiple ISP repairs; frequent unexplained disconnections affect work and daily use; ISP customer service is uncooperative; your contract is expiring and another ISP offers better value; or a new ISP has deployed FTTH fibre in your building while you are currently on FTTB.
Check your current contract's expiry date and early termination penalties. Many ISPs have 18-24 month contracts with exit fees. Start comparing alternatives 1-2 months before expiry. You can also use competing offers as leverage to negotiate a renewal deal with your current ISP.
故障排除流程總覽 Troubleshooting Flowchart Summary
1. 重啟路由器 + ONU（等 30 秒）
2. 檢查實體線路同指示燈
3. 有線測試排除 WiFi 問題
4. 正確方法做速度測試
5. 比較繁忙 / 非繁忙時段速度
6. 優化 WiFi 頻道 + 路由器擺位
7. 更改 DNS 設定
8. 更新路由器韌體
9. 致電 ISP（帶齊證據）
10. 向 OFCA 投訴（ISP 唔處理時）
11. 考慮轉台（問題持續無解時）
大部分寬頻問題其實都可以喺前幾個步驟解決。記住：先排除自己可以控制嘅因素（路由器、WiFi、線路），再去追究 ISP 嘅責任。有理有據嘅投訴先至最有效。
Most broadband issues can actually be resolved within the first few steps. Remember: eliminate factors within your control first (router, WiFi, cabling), then hold your ISP accountable. Complaints backed by evidence are the most effective.