Mobile L2TP Technical: Difference between revisions

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__NOTOC__<indicator name="L2TP">[[File:~~FBimgtunnel~~.svg|link=:Category:L2TP|30px|Back up to the L2TP Category]]</indicator>

__NOTOC__<indicator name="L2TP">[[File:Menu-L2TP.svg|link=:Category:L2TP|30px|Back up to the L2TP Category]]</indicator>

An L2TP tunnel is established using the pre-agreed IP addresses, hostname and shared secret. Note that if your LNS rejects the tunnel connection, or fails to respond to the SCCRQ or a subsequent HELLO, then it will be ~~black listed~~ for 5 minutes allowing further connections to go to the fall-back LNSs.

An L2TP tunnel is established using the pre-agreed IP addresses, hostname and shared secret. Note that if your LNS rejects the tunnel connection, or fails to respond to the SCCRQ or a subsequent HELLO, then it will be block for 5 minutes allowing further connections to go to the fall-back LNSs.

Once the tunnel is established, a session is established for each connecting data SIM.

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*User-Name passed is what is provided by the mobile which is usually blank. Do not use the password 'password' as this will not be passed through.

*IPv6 is not available yet, but is planned for the future if possible.

==Connect Speed==

We've seen various devices give odd Connect Speed settings when they connect. EG, OSX sends:

Connect Speed: 1000000

And a Pfsense has been seen to send 10Mbit/s and even the source code had it hard coded to 10Mbit/s.

[[File:L2TP OS X speed weirdness.png|thumbnail|TCP Dump of OSX L2TP highlighting the 'Connect Speed']]

This means that it is asking for a 1Mbit/s connection. This does not looks like it's configurable either.

From May 2016 we ignore the Connect Speed, and simply limit the speed to 100Mbit/s at our side.