[PageOutline] = The Gb proxy =

The purpose of the Gb proxy is to aggregate the Gb links of multiple
BSS's and present them in one Gb link to the SGSN.

More specifically, the Gb proxy terminates the NS-VCs of each BSS
locally. Furthermore, it establishes one NS-VC with the SGSN.

The proxy then forwards NS-DUs (BSSGP PDUs) between the SGSN and the
respective BSS (and vice versa).

Configuring and using osmo-gbproxy
FIXME Advanced use cases

=== Cascading proxies ===

You can also cascade multiple Gb proxies behind each other, where a number
of BSS connect to one Gb proxy, which in turn connects to another Gb proxy,
which then finally connects to the SGSN.

The reason for this type of use can be broken or limited Gb implementations
in proprietary BSS equipment, which fails to re-connect the Gb link after some
intermittent network outage.

Design documentation

There's a more detailed [wiki:osmo-gbproxy_design design description] outlining
details of the proxy.