Signal, ports & traceroute — pro network apps for phones

Read your real signal strength in dBm

Signal bars are a rough gauge, not a measurement. Every manufacturer maps signal to bars differently, so three bars on one phone can be two on another at the exact same spot. The real number is dBm: it is always negative, and closer to zero is better — -60 dBm is a strong signal, -110 dBm is effectively none.

You can read it manually today. On Android, open Settings → About phone → SIM status and find "Signal strength"; on iPhone, dial *3001#12345#* to open Field Test Mode. The Cellular tool will put the same reading — dBm, RSRP, RSRQ, network type and cell details — one tap away, no menu digging. Interpret what you see with this scale:

• -50 to -79 dBm — excellent: full-speed data, calls hold everywhere.
• -80 to -89 dBm — good: everything works, heavy downloads a touch slower.
• -90 to -99 dBm — fair: pages load, video may buffer, calls occasionally rough.
• -100 to -109 dBm — poor: expect drops, stalls and battery drain.
• -110 dBm or lower — effectively no usable signal.

Bars vs dBm — how to compare carriers fairly

Most articles about weak signal are written by booster vendors whose answer is always an amplifier. A fair carrier comparison needs no purchases — just readings. Stand in the same spot at the same time of day and note the dBm and network type for each SIM you are comparing — in Egypt that usually means Vodafone, Orange and WE. Repeat at home, at work and along your commute over a few days.

Two honesty rules make the comparison meaningful. First, compare like with like: a strong 4G signal at -75 dBm usually beats a weak 5G one at -105 dBm in real use, so read the network type next to the number. Second, never judge on one reading — signal shifts with buildings, floors and even weather. Trends over a week tell you which network actually covers your places; a single screenshot tells you nothing.

Scan a host for open TCP ports — responsibly

An open port is a service listening for connections — a web server on 443, a remote login on 22. The Port Scanner attempts TCP connections across a port range you choose and reports which ones accept, straight from your phone. The scan travels directly from your device to the target; nothing passes through Carbide's servers. Common ports worth knowing:

• 22 — SSH (remote login) and 21 — FTP (file transfer).
• 80 — HTTP and 443 — HTTPS (web servers).
• 25 and 587 — SMTP (mail) and 53 — DNS.
• 3389 — RDP (remote desktop) and 8080 — alternative web port.

Traceroute from your phone — find where lag starts

Ping tells you the total delay to a host; Traceroute tells you where that delay comes from. It probes the route hop by hop, so every router between you and the server answers with its own latency. To use it: enter the host (a game server, or any site that feels slow), start the trace, and read the hops top to bottom. Expect a list of roughly 8 to 20 rows, each with a latency.

Reading it is simple: hop 1 is your own router and should sit at a few milliseconds — if it shows 100 ms or more, your Wi-Fi is the problem, not the internet. The next few hops are your ISP; the rest is the wider network. A row of "* * *" is a router that ignores probes — only worry if latency jumps after it and stays high. The hop where delay first climbs and never recovers is your culprit. Pair the trace with the browser Ping tool for continuous latency, jitter and loss — the speed, ping and jitter guide explains what good numbers look like.

Start in your browser — the checks you can run today

While the app is on its way, the everyday half of network diagnostics already runs free in your browser, no sign-up. Ping measures latency, jitter and loss to any host using timed HTTPS requests — not raw ICMP, and we say so plainly. Speed Test times real transfers against test servers to measure download, upload, ping and jitter in one run. Network Info reads your browser-visible connection type and round-trip time locally, and IP Info shows your public IP with city and ISP — that one fetches from live lookup sources, sending only a query, never your files. The what is my IP post explains what the address reveals.

The order of operations: browser first to confirm the line is actually slow, then the app tools to find out whether it is the radio, a port or the path. The network diagnostics guide walks the full sequence.

Why a browser can't do any of this

Browsers deliberately cannot read the cellular modem, open raw TCP sockets to arbitrary ports, or send the custom ICMP probes a trace needs. That sandbox protects you from malicious websites — but it also means no web page, ours included, can honestly offer a dBm reading, a port scan or a real traceroute. Anyone claiming otherwise is estimating, not measuring.

That is why these three live in the Carbide app, next to the other radio-level tools: WiFi Analyzer for channels and signal, Router Info for your gateway, DHCP and DNS, and LAN Devices to see everything on your network — covered in who is on my WiFi. The app is free, needs no account, runs its measurements on your device, and is coming soon to Android and iOS.

Frequently asked questions