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diff --git a/doc/manuals/chapters/net.adoc b/doc/manuals/chapters/net.adoc new file mode 100644 index 000000000..06be4bad2 --- /dev/null +++ b/doc/manuals/chapters/net.adoc @@ -0,0 +1,154 @@ +[[net]] +== Configuring the Core Network + +The core network parameters are configured by the config file (as in `osmo-msc +-c osmo-msc.cfg`). The config file is parsed by the VTY, which is also +available via telnet in the running `osmo-msc` instance. Be aware that even +though you may be able to change these parameters without restarting +`osmo-msc`, some may not take immediate effect, and it is safest to use the +config file to have these parameters set at startup time. + +The core network parameters are found in the `config` / `network`. + +A full reference to the available commands can be found in the _OsmoMSC VTY +reference manual_ <<vty-ref-osmomsc>>. This section describes only the most +commonly used settings. + +Here is an overview of the config items, described in more detail below: + +---- +network + network country code 262 + mobile network code 89 + mm info 1 + short name OsmoMSC + long name OsmoMSC + authentication required + encryption a5 3 +---- + +[TIP] +==== +Use the telnet VTY interface to query the current configuration of a running +`osmo-msc` process: + +---- +$ telnet localhost 4254 +OsmoMSC> enable +OsmoMSC# show running-config +---- + +Some parameters may be changed without restarting `osmo-msc`. To reach the +`network` node, enter: + +---- +OsmoMSC> enable +OsmoMSC# configure terminal +OsmoMSC(config)# network +OsmoMSC(config-net)# short name Example-Name +OsmoMSC(config-net)# exit +OsmoMSC(config)# +---- + +The telnet VTY features tab-completion as well as context sensitive help shown +when entering a `?` question mark. + +You can always use the `list` VTY command or enter `?` on the blank prompt to +get a list of all possible commands at the current node. +==== + + +=== MCC/MNC + +The key identities of every GSM PLMN is the Mobile Country Code and the Mobile +Network Code. They are identical over the entire network. In most cases, the +MCC/MNC will be allocated to the operator by the respective local regulatory +authority. For example, to set the MCC/MNC of 262-89, have this in your +osmo-msc.cfg: + +---- +network + network country code 262 + mobile network code 89 +---- + + +=== Configuring MM INFO + +The _MM INFO_ procedure can be used after a successful _LOCATION UPDATE_ in +order to transmit the human-readable network name as well as local time zone +information to the MS. By default, _MM INFO_ is not active, i.e. `0`. Set to `1` +to activate this feature: + +---- +network + mm info 1 + short name OsmoMSC + long name OsmoMSC +---- + +[NOTE] +==== +Not all phones support the MM INFO procedure. If a phone is not +factory-programmed to contain the name for your MCC/MNC, it will likely only +provide a numeric display of the network name, such as _262-89_, or show the +country code transformed into a letter, such as _D 89_. +==== + +The time information transmitted is determined by the local system time of the +operating system on which OsmoMSC is running. + + +=== Authentication + +Authorized subscribers must be entered in the HLR database, see the _OsmoHLR +reference manual_ <<userman-osmohlr>>. If authentication tokens (such as KI for +2G, or K and OP/OPC for UMTS) are present in the HLR, OsmoMSC will only attach +a subscriber after successful authentication. + +If no authentication keys are present in the HLR for a given subscriber, +OsmoMSC will attach the subscriber _without_ authentication. You can reject +subscribers that lack authentication info in the HLR with this setting: + +---- +network + authentication required +---- + +=== Ciphering + +To enable ciphering on the radio link, authentication must take place first: +the Kc resulting from authentication is the key used for ciphering. Hence, all +subscribers must have authentication tokens available in the HLR for ciphering. + +The MS, BTS and MSC must agree on a ciphering algorithm to use. + +- The MS sends its supported ciphering algorithms via Classmark IEs during + Location Updating. +- Typically the BSC needs to know which A5 ciphers are supported by connected + BTSes. +- Finally, OsmoMSC may impose that specific A5 ciphers shall not be considered. + +It is the responsibility of the BSC to then pick an A5 cipher that satisfies +all requirements. + +- In OsmoMSC, A5/0 means that ciphering is turned off. ++ +---- +network + encryption a5 0 +---- + +- A5/1 and A5/3 are currently supported by Osmocom. ++ +---- +network + encryption a5 3 +---- + +- Never use A5/2: it is an "export grade cipher" and has been deprecated for + its low ciphering strength. + +NOTE: At the time of writing, OsmoMSC supports setting only a single A5 cipher, +while it should be able to allow a set of ciphers. This is subject to ongoing +development. |