110 lines
3.0 KiB
Plaintext
110 lines
3.0 KiB
Plaintext
== Gb interface using libosmogb
|
|
|
|
'libosmogb' is part of the libosmocore.git repository and implements the
|
|
Gb interface protocol stack consisting of the NS and BSSGP layers. It
|
|
is used in a variety of Osmocom project, including OsmoSGSN,
|
|
OsmoGbProxy and OsmoPCU.
|
|
|
|
This section describes the configuration that libosmogb exposes via the
|
|
VTY.
|
|
|
|
=== Gb interface configuration
|
|
|
|
==== NS-over-UDP configuration
|
|
|
|
The GPRS-NS protocol can be encapsulated in UDP/IP. This is the default
|
|
encapsulation for IP based GPRS systems.
|
|
|
|
.Example: GPRS NS-over-UDP configuration
|
|
----
|
|
OsmoSGSN(config-ns)# encapsulation udp local-ip 127.0.0.1 <1>
|
|
OsmoSGSN(config-ns)# encapsulation udp local-port 23000 <2>
|
|
----
|
|
<1> Set the local side IP address for NS-over-UDP
|
|
<2> Set the local side UDP port number for NS-over-UDP. 23000 is the default
|
|
|
|
==== NS-over-FR-GRE configuration
|
|
|
|
The GPRS-NS protocol can alternatively be encapsulated over Frame Relay
|
|
(FR). Traditionally this is communicated over SDH/PDH media, which we
|
|
don't support. However, we can encapsulate the FR in GRE, and then that
|
|
in IP.
|
|
|
|
The resulting NS-FR-GRE-IP stack can be converted by an off-the-shelf
|
|
router with FR and IP support.
|
|
|
|
.Example: GPRS NS-over-FR-GRE configuration
|
|
----
|
|
OsmoSGSN(config-ns)# encapsulation framerelay-gre enabled 1 <1>
|
|
OsmoSGSN(config-ns)# encapsulation framerelay-gre local-ip 127.0.0.1 <2>
|
|
----
|
|
<1> Enable FR-GRE encapsulation
|
|
<2> Set the local side IP address for NS-over-FR-GRE
|
|
|
|
==== NS Timer configuration
|
|
|
|
The NS protocol features a number of configurable timers.
|
|
|
|
.List of configurable NS timers
|
|
|===
|
|
|tns-block|(un)blocking timer timeout (secs)
|
|
|tns-block-retries|(un)blocking timer; number of retries
|
|
|tns-reset|reset timer timeout (secs)
|
|
|tns-reset-retries|reset timer; number of retries
|
|
|tns-test|test timer timeout (secs)
|
|
|tns-alive|alive timer timeout(secs)
|
|
|tns-alive-retries|alive timer; number of retries
|
|
|===
|
|
|
|
=== Examining Gb interface status
|
|
|
|
There are several commands that can help to inspect and analyze the
|
|
currently running system status with respect to the Gb interfaces.
|
|
|
|
.Example: Inspecting NS state
|
|
----
|
|
OsmoSGSN> show ns
|
|
Encapsulation NS-UDP-IP Local IP: 127.0.0.1, UDP Port: 23000
|
|
Encapsulation NS-FR-GRE-IP Local IP: 0.0.0.0
|
|
----
|
|
FIXME
|
|
|
|
FIXME: show ns stats
|
|
|
|
.Example: Inspecting BSSGP state
|
|
----
|
|
----
|
|
FIXME
|
|
|
|
FIXME: show nse
|
|
|
|
=== FIXME
|
|
|
|
==== Blocking / Unblocking / Resetting NS Virtual Connections
|
|
|
|
The user can manually perform operations on individual NSVCs:
|
|
|
|
* blocking a NSVC
|
|
* unblocking a NSVC
|
|
* resetting a NSVC
|
|
|
|
The VTY command used for this is the `nsvc (nsei|nsvci) <0-65535>
|
|
(block|unblock|reset)` command available from the ENABLE node.
|
|
|
|
|
|
=== Gb interface logging filters
|
|
|
|
There are some Gb-interface specific filters for the libosmocore
|
|
logging subsystem, which can help to reduce the logged output to
|
|
messages pertaining to a certain NS or BSSGP connection only.
|
|
|
|
.Example: enabling a log filter for a given NSEI
|
|
----
|
|
OsmoSGSN> logging filter nsvc nsei 23
|
|
----
|
|
|
|
.Example: enabling a log filter for a given NSVCI
|
|
----
|
|
OsmoSGSN> logging filter nsvc nsvci 23
|
|
----
|