Version 1 - History - Ladder diagrams for key procedures - OsmoBSCNAT - Open Source Mobile Communications

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osmith

h1. Ladder diagrams for key procedures

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h2. MO call

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Illustrating how BSSMAP Assignment Request, Assignment Complete, Clear Command and Clear Complete is patched while going through BSCNAT as well as the related MGCP logic.

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{{mscgen_link()

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msc {

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	hscale = "2";

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	bsc	[label="BSC\n"],

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	mgwbsc	[label="MGW-BSC\nIP: X"],

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	bscnat	[label="BSCNAT\n"],

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	mgwnat	[label="MGW-NAT\nIP: Y"],

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	msc_	[label="MSC\n"],

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	mgwmsc	[label="MGW-MSC\nIP: Z"];

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	bsc box mgwmsc		[label="DTAP omitted from diagram, assuming Call Confirmed"];

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	msc_	=> mgwmsc	[label="MGCP CRCX\nrtpbridge/*@msc"];

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	msc_	<= mgwmsc	[label="MGCP OK (Port: M)\nrtpbridge/1@msc"];

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	|||;

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	bscnat	<= msc_		[label="BSSMAP Assignment Request (AoIP: IP Z, Port M)"];

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	|||;

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	bscnat	box mgwnat	[label="Allocate CN-side connection"];

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	bscnat	=> mgwnat	[label="MGCP CRCX (CI: IP Z, Port M)\nrtpbridge/*@nat"];

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	bscnat	<= mgwnat	[label="MGCP OK (Port C)\nrtpbridge/1@nat"];

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	bscnat	box mgwnat	[label="Allocate RAN-side connection"];

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	bscnat	=> mgwnat	[label="MGCP CRCX\nrtpbridge/1@nat"];

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	bscnat	<= mgwnat	[label="MGCP OK (Port R)\nrtpbridge/1@nat"];

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	|||;

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	bsc	<= bscnat	[label="BSSMAP Assignment Request (AoIP: IP Y, Port R)"];

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	|||;

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	bsc	box mgwbsc	[label="Allocate BTS-side connection"];

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	bsc	=> mgwbsc	[label="MGCP CRCX\nrtpbridge/*@bsc"];

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	bsc	<= mgwbsc	[label="MGCP OK (Port A)\nrtpbridge/1@bsc"];

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	bsc	=> mgwbsc	[label="MGCP MDCX (CI: IP W, Port: B)\nrtpbirdge/1@bsc"];

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	bsc	<= mgwbsc	[label="MGCP OK (Port A)\nrtpbridge/1@bsc"];

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	bsc	box mgwbsc	[label="Allocate BSCNAT-side connection"];

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	bsc	=> mgwbsc	[label="MGCP CRCX (CI: IP Y, Port R)\nrtpbridge/1@bsc"];

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	bsc	<= mgwbsc	[label="MGCP OK (Port E)\nrtpbridge/1@bsc"];

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	|||;

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	bsc	=> bscnat	[label="BSSMAP Assignment Complete (AoIP: IP X, Port E)"];

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	|||;

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	bscnat	=> mgwnat	[label="MGCP MDCX (CI: IP X, Port E)\nrtpbridge/1@nat"];

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	bscnat	<= mgwnat	[label="MGCP OK (Port R)\nrtpbirdge/1@nat"];

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	|||;

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	bscnat	=> msc_		[label="BSSMAP Assignment Complete (AoIP: IP Y, Port C)"];

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	|||;

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	msc_	=> mgwmsc	[label="MGCP MDCX (CI: IP Y, Port C)\nrtpbridge/1@msc"];

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	msc_	<= mgwmsc	[label="MGCP OK (Port M)\nrtpbridge/1@msc"];

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	...;

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	bsc	box mgwmsc	[label="Voice call in progress"];

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	...;

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	msc_	=> mgwmsc	[label="MGCP DLCX\nrtpbridge/1@msc"];

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	mgwmsc	=> msc_		[label="MGCP OK\nrtpbridge/1@msc"];

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	msc_	=> mgwmsc	[label="MGCP DLCX\nrtpbridge/1@msc"];

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	mgwmsc	=> msc_		[label="MGCP OK\nrtpbridge/1@msc"];

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	|||;

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	msc_	=> bscnat	[label="BSSMAP Clear Command"];

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	|||;

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	bscnat	box mgwnat	[label="Drop whole endpoint (both RAN-side and CN-side CI)"];

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	bscnat	=> mgwnat	[label="MGCP DLCX\nrtpbridge/1@nat"];

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	bscnat	<= mgwnat	[label="MGCP OK\nrtpbridge/1@nat"];

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	|||;

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	bscnat	=> bsc		[label="BSSMAP Clear Command"];

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	|||;

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	bsc	=> mgwbsc	[label="MGCP DLCX\nrtpbridge/1@nat"];

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	bsc	<= mgwbsc	[label="MGCP OK\nrtpbridge/1@nat"];

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	bsc	=> mgwbsc	[label="MGCP DLCX\nrtpbridge/1@nat"];

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	bsc	<= mgwbsc	[label="MGCP OK\nrtpbridge/1@nat"];

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	|||;

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	bsc	=> bscnat	[label="BSSMAP Clear Complete"];

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	|||;

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	|||;

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	bscnat	=> msc_	[label="BSSMAP Clear Complete"];

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	|||;

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}}

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Ladder diagrams for key procedures » History » Version 1