The VTY option to bind the virtual Um multicast to a specific
network interface has existed ever since osmo-bts-virtual was
first merged to the repo. However, embarrassingly, until today
it never did anything, i.e. the code to actually perform the bind
was missing.
Depends: libosmocore.git Ib52d22710020b56965aefcef09bde8247ace4a9c
Change-Id: I303f2e616d2d32b5a8005c3dcf0f5fad19ad3445
Related: OS#2966
This can be used to determine the multicast TTL packet and hence
how far the packet will propagate in the network. If you want to
operate the virtual Um only on your own machine, a TTL of 0 would
prevent the packets from ever being transmitted on your local
ethernet segment.
Change-Id: I18a9f93b764aee4e1dc68a1c6ac4d078e52ca61d
Related: OS#2966
The addresses in the original code make little sense:
* 224.0.0.1 is "All systems on this subnet" and not routed
outside the local ethernet segment
* 225.0.0.1 is in a RESERVED range that shouldn't be used
Change-Id: Iba1ae69f3f193a33f1da343c6562f67bd8d3557f
This patch adds a virtual physical layer designed to simulate the
Um air interface between BTS and MS. It does so by encapsulating MAC
blocks (Layer 2 PDUs) via GSMTAP and sending them through multicast UDP
streams, both in uplink and in downlink.
The purpose of this is enable testing without any radio hardware or
related licenses.
OsmocomBB has recently received as similar patch-set, adding a virty_phy
executable that can be run on a PC instead of the classic 'layer1'
firmware on a real phone.
Using GSMTAP means that one can use unmodified wireshark to decode the
messages exchanged on the virtual Um layer.
This code was originally started by Harald in January 2016, continued
by Sebastian Stumpf in late 2016 and early 2017, and finally completed
by Harald in July 2017.
Change-Id: I1bf7670975b1e367c1c62983020865a043542622
Harald Welte