Osmo-gbproxy » History » Revision 9
Revision 8 (laforge, 02/20/2016 08:57 PM) → Revision 9/20 (laforge, 02/21/2016 07:49 AM)
{{>toc}} h1. 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. Source code available as part of [[OpenBSC]] repository: <pre> git clone git://git.osmocom.org/openbsc.git </pre> The proxy then forwards NS-DUs (BSSGP PDUs) between the SGSN and the respective BSS (and vice versa). {{graphviz_link() <pre> <code class="graphviz"> digraph G { rankdir=LR; nanobts1->OpenBSC [ label="Abis/IP" ]; nanobts2->OpenBSC [ label="Abis/IP" ]; nanobts1->gb_proxy [ label="Gb/IP" ]; nanobts2->gb_proxy [ label="Gb/IP" ]; gb_proxy->SGSN [ label="Gb/IP or\nGb/FR/GRE/IP" ]; nanobts2 [ label = "nanoBTS 2" ]; nanobts1 [ label = "nanoBTS 1" ]; OpenBSC [[OpenBSC]] [ label = "OpenBSC" ] } }} </code></pre> {{child_pages}} h2. Configuring and using osmo-gbproxy Like other programs in this project, osmo-gbproxy accepts a number of command line arguments but is generally configured by a configuration file (which can be interactively created/edited from the VTY). The command line arguments are: <pre> -h --help this text -d option --debug=DNS:DGPRS,0:0 enable debugging -c --config-file filename The config file to use. -s --disable-color -T --timestamp Prefix every log line with a timestamp -V --version. Print the version of [[OpenBSC]]. -e --log-level number. Set a global loglevel. </code></pre> There is a wiki page [[osmo-gbproxy_VTY]] with a reference for all VTY commands h2. Advanced use cases h3. 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. h2. Design documentation There's a more detailed [[osmo-gbproxy_design|design description]] outlining details of the proxy.