This is an original planning guide. It is not a vendor manual, an official standard, or legal advice. Example addresses use documentation ranges. Review every command before you paste it.
What this hour is for
A codec uses a steady rate, and the packet overhead is extra. The calculators turn a call count and a codec into a sketch. They do not place a call. A MOS estimate is a model, not a promise that users will be happy.
Write the codec, the number of concurrent calls, and the link. A guess of every employee on a call at once is a guess you label. Do not size a provider link you do not administer.
One site. The marking of voice packets is a later ticket. This hour is the number.
The change you can finish
Apply nothing during the writing of the note. When the lab window opens, it is one change on the device named in the ticket. Read the draft, then the device, then decide.
Rollback is the file or the revision you saved first. You do not invent a rollback after the only copy is gone.
- Write the codec.
- Write concurrent calls.
- Read the bandwidth.
- Add overhead if the calculator separated it.
- Do not place a test flood.
- Stop.
Mistakes that outlive the command
How to Size Bandwidth for VoIP goes wrong in a small set of ways. The list is here so the ticket can forbid them before the window.
- Ignoring packet overhead.
- A call count you did not label as a guess.
- Flooding the link to prove it.
- Sizing someone else's circuit.
- Changing QoS in the same hour.
Decisions to write down
One decision for How to Size Bandwidth for VoIP: Codec and call count are written. Overhead is included. The link is yours. No flood was sent. And qoS waits.
Checks before you call it done
Confirm this before you call the change done: The codec is written. The call count is written. The bandwidth is written. No test flood was sent. And no marking was changed. If one of those fails, stop.
Before you leave the device
How to Size Bandwidth for VoIP ends when the hostname on the device matches the hostname in the ticket. If it does not, you are on the wrong box. Stop. A command that succeeded on the wrong box is not progress.
The draft stays a draft until a person has read the names in it. A generator does not log into the device and does not know which interface is the uplink. You delete a line that names a device, a zone, or a prefix you did not write down.
0.0.0.0/0 is not kept because a sample included it. A source you can say is the source you keep. 192.0.2.0/24, 198.51.100.0/24, 203.0.113.0/24, and 2001:db8::/32 are documentation. They belong in the note. They are not prefixes you type onto a production device because they appeared in a draft.
prompt-for-this is a reminder that a secret is missing. It is not a password, a key, a community string, or a pre-shared key you save in the ticket or in git. The real secret stays in the store.
One change is the window. A VLAN and a routing protocol and a VPN do not share it. If two things move and the result is wrong, you will not know which one did it. The next feature waits for its own page.
If the same step fails twice, stop for the day. The failure is the result. Adding a forum command beside a half-applied config produces a device nobody can rebuild. Restore the copy you took first.
A second person reads the device name and the change aloud. If they cannot find them in the ticket, the note is not done. Silence is not agreement. Then leave the device alone.
This page is a planning guide. It is not a vendor manual, not an official standard, and not a permission to touch a network you do not administer. The pillar guide owns the wider design. This page owns one lab proof.
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