---
title: Theoretical maximum speed calculator
has_children: false
nav_order: 4
description: Tool for calculating maximum speeds
---
<h1>Ethernet calculator</h1>
<form id="eth-speed-mtu">
<div class="form-floating mb-3">
<input type="number" class="form-control" placeholder="MTU L2" name="mtu" id="mtu" value="1500" min="1000" max="10000">
<label for="mtu">MTU L2 (no overhead for PPPoE/MAP, only Ethernet PPPoE)</label>
</div>
<div class="form-floating mb-3">
<div class="mb-3">
<div class="form-check form-check-inline">
<input class="form-check-input" type="radio" id="ip4" name="ip" value="4" checked>
<label class="form-check-label" for="ip4">IPv4</label>
</div>
<div class="form-check form-check-inline">
<input class="form-check-input" type="radio" id="ip6" name="ip" value="6">
<label class="form-check-label" for="ip6">IPv6</label>
</div>
</div>
</div>
<select class="form-select mb-3" placeholder="IPv4 L2 protocol" name="ipv4protocol" id="ipv4protocol">
<option disabled selected>Select a Protocol</option>
<option value="ipoe">IPoE</option>
<option value="pppoe">PPPoE</option>
<option value="map-t">MAP-T</option>
<option value="map-e">MAP-E/4in6</option>
</select>
<select class="form-select mb-3" placeholder="IPv6 L2 protocol" name="ipv6protocol" id="ipv6protocol" disabled>
<option disabled selected>Select a Protocol</option>
<option value="ipoe">IPoE</option>
<option value="pppoe">PPPoE</option>
</select>
<select class="form-select mb-3" placeholder="Speed" name="speed">
<option disabled selected>Select a link speed</option>
<option value="10">10 Mbps</option>
<option value="100">100 Mbps</option>
<option value="200">200 Mbps</option>
<option value="500">500 Mbps</option>
<option value="1000">1 Gbps</option>
<option value="2500">2.5 Gbps</option>
<option value="5000">5 Gbps</option>
<option value="10000">10 Gbps</option>
</select>
<div class="mb-3">
<input type="submit" class="btn btn-primary" value="Calculate!">
</div>
<div class="form-floating mb-3">
<input readonly class="form-control" type="number" id="maxSpeed" placeholder="Theoretical maximum speed">
<label for="maxSpeed">Theoretical maximum speed (Mbps)</label>
</div>
<div class="form-floating mb-3">
<input readonly class="form-control" type="number" id="overhead" placeholder="Ethernet overhead (%)">
<label for="overhead">Ethernet overhead (%)</label>
</div>
</form>
<h1>Gpon calculator</h1>
<form id="gpon-speed-mtu">
<div class="form-floating mb-3">
<input step="1" type="number" class="form-control" placeholder="ONT number" name="gpon-ont" id="gpon-ont" value="10" min="1" max="128" required>
<label for="gpon-ont">ONT number</label>
</div>
<div class="form-floating mb-3">
<input step="1" type="number" class="form-control" placeholder="GEM frame number" name="gpon-gem" id="gpon-gem" value="26" min="1" max="40" required>
<label for="gpon-gem">GEM frame number</label>
</div>
<div class="mb-3">
<div class="form-check form-check-inline">
<input class="form-check-input" type="radio" id="gpon-ip4" name="gpon-ip" value="4" checked>
<label class="form-check-label" for="gpon-ip4">IPv4</label>
</div>
<div class="form-check form-check-inline">
<input class="form-check-input" type="radio" id="gpon-ip6" name="gpon-ip" value="6">
<label class="form-check-label" for="gpon-ip6">IPv6</label>
</div>
</div>
<select class="form-select mb-3" placeholder="IPv4 L2 protocol" name="gpon-ipv4protocol" id="gpon-ipv4protocol" required>
<option disabled selected>Select a Protocol</option>
<option value="ipoe">IPoE</option>
<option value="pppoe">PPPoE</option>
<option value="map-t">MAP-T</option>
<option value="map-e">MAP-E/4in6</option>
</select>
<select class="form-select mb-3" placeholder="IPv6 L2 protocol" name="gpon-ipv6protocol" id="gpon-ipv6protocol" disabled required>
<option disabled selected>Select a Protocol</option>
<option value="ipoe">IPoE</option>
<option value="pppoe">PPPoE</option>
</select>
<div class="mb-3">
<input type="submit" class="btn btn-primary" value="Calculate!">
</div>
<div class="form-floating mb-3">
<input type="number" class="form-control" placeholder="GPON Average Ethernet Frame Size (Byte)" name="gpon-average-packet-size" id="gpon-average-packet-size" readonly>
<label for="gpon-average-packet-size">GPON Average Ethernet Frame Size (Byte) must be inside 1000-1500</label>
</div>
<div class="form-floating mb-3">
<input type="number" class="form-control" placeholder="Theoretical maximum speed (Gbps)" name="gpon-maxSpeed" id="gpon-maxSpeed" readonly>
<label for="gpon-maxSpeed">Theoretical maximum speed (Mbps)</label>
</div>
<div class="form-floating mb-3">
<input type="number" class="form-control" placeholder="GPON overhead (%)" name="gpon-overhead" id="gpon-overhead" readonly>
<label for="gpon-overhead">GPON overhead (%)</label>
</div>
</form>
<script>
var form = document.getElementById('eth-speed-mtu');
var radioIp = document.getElementsByName('ip');
[...radioIp].forEach(el => {el.addEventListener('change', (event) => {
var ip = document.querySelector('input[name="ip"]:checked').value;
document.getElementById('ipv4protocol').disabled = (ip === '6');
document.getElementById('ipv6protocol').disabled = (ip === '4');
});
});
form.addEventListener('submit',(event) => {
var formdata = new FormData(form);
event.preventDefault();
var overheadipv4 = {
"ipoe" : 20,
"pppoe" : 28,
"map-t" : 40,
"map-e" : 60,
};
var overheadipv6 = {
"ipoe" : 40,
"pppoe" : 48,
};
var overheadtcp = 20;
var overheadeth = 14;
var overheadfcs = 4;
var overheadgap = {
'10' : 5.875,
'100' : 12,
'200' : 8,
'500' : 8,
'1000' : 8,
'2500' : 5,
'5000' : 5,
'10000' : 5,
};
var preamble = 8;
var cip = formdata.get('ip');
var coverheadip = formdata.get('ip') === '4' ? overheadipv4[formdata.get('ipv4protocol')] : overheadipv6[formdata.get('ipv6protocol')];
var mtu = formdata.get('mtu');
var mss = mtu - coverheadip;
var overhead = overheadtcp + overheadeth + overheadfcs + overheadgap[formdata.get('speed')] + preamble + coverheadip;
document.getElementById('overhead').value = overhead/mss * 100;
var th = mss /(overhead + mss);
document.getElementById('maxSpeed').value = th * formdata.get('speed');
});
var formgpon = document.getElementById('gpon-speed-mtu');
var radioIp = document.getElementsByName('gpon-ip');
[...radioIp].forEach(el => {el.addEventListener('change', (event) => {
var ip = document.querySelector('input[name="gpon-ip"]:checked').value;
document.getElementById('gpon-ipv4protocol').disabled = (ip === '6');
document.getElementById('gpon-ipv6protocol').disabled = (ip === '4');
});
});
formgpon.addEventListener('submit',(event) => {
var formdata = new FormData(formgpon);
event.preventDefault();
var gtc = 38880;
var overheadgem = 5;
var overheadpcbd = 30 + 8*formdata.get('gpon-ont');
var overheadipv4 = {
"ipoe" : 20,
"pppoe" : 28,
"map-t" : 40,
"map-e" : 60,
};
var overheadipv6 = {
"ipoe" : 40,
"pppoe" : 48,
};
var overheadtcp = 20;
var overheadeth = 14;
var overheadfcs = 4;
var cip = formdata.get('gpon-ip');
var coverheadip = formdata.get('gpon-ip') === '4' ? overheadipv4[formdata.get('gpon-ipv4protocol')] : overheadipv6[formdata.get('gpon-ipv6protocol')];
var overheadframeeth = overheadtcp + overheadeth + overheadfcs + coverheadip;
var overheadgtc = overheadgem + formdata.get('gpon-gem') * (overheadpcbd+overheadframeeth);
var payload = gtc - overheadgtc;
document.getElementById('gpon-average-packet-size').value = payload/formdata.get('gpon-gem');
document.getElementById('gpon-overhead').value = overheadgtc/payload * 100;
var th = payload /gtc;
document.getElementById('gpon-maxSpeed').value = th * 2.48832;
});
</script>
