IPv6 User Plane¶
As of August 2017, User Plane IPv6 support has been implemented for OpenGGSN and OsmoGGSN. This means you can not only provide IPv4 addresses to mobile terminals, but also IPv6 prefixes.
Please see the following notes:
- OpenGGSN currently can only operate either an IPv4 pool or an IPv6 pool. If you need both, you will have to either
- run two OpenGGSN instances in parallel, e.g. each on a separate GTP-side IP address and route different APNs from the SGSN (such as OsmoSGSN to the different OpenGGSN instances/IPs.
- switch to the OpenGGSN successor OsmoGGSN
- You must allocate a dynamic IP address pool sufficiently large, as every PDP context gets its own /64 prefix. So a /56 prefix gives you 256 /64 prefixes, i.e. 256 PDP contexts
- IPv6 is only supported on the user plane, not on the outer (GTP transport) layer between SGSN and GGSN!
- Linux Kernel_GTP does not support IPv6 at this point, so you will have to handle GTP-U in OpenGGSN
- See https://osmocom.org/issues/2418 for example config files and pcap traces
- See http://laforge.gnumonks.org/blog/20170809-osmocom-ipv6 about technical background