Configuring a new APN

The NITOS LTErf service, is allowing the experimenters to interact within their reservation slot with the base stations, EPC networks and datapaths for their experiment.

This tutorial demonstrates how we can define a new APN that can be used for the LTE network, and configuring the subscribers that are available in the NITOS testbed.

Updating an existing APN

Currently the firmware on the commercial femtocells is allowing only one APN to be used. This will be resolved in a future update. In order to change the APN configuration at the SiRRAN EPC network, you will have to send the following commands:

  wget -qO- http://lterf:5054/lterf/epc/get?function=getAPNList | xml_pp 

The command will return you the available APN profiles configured at the EPC network. If you want more details about the existing APN used, you can send the following command:

 wget -qO- "http://lterf:5054/lterf/epc/get?function=getAPN&args=default" | xml_pp 

the command will return you an XML file with the APN configuration, regarding the IP address set to the PDN-GW, the netmask used, the primary and secondary DNS servers used by the LTE UE, and the DHCP range starting and ending IP addresses. to update this configuration, you will have to send the following command:

 wget -qO- http://lterf:5054/lterf/epc/set?function=updateAPN&args=APNName,PGWIPADDR,NETMASK,PRIMARY_DNS,SECONDARY_DNS,DHCP_START_RANGE,DHCP_END_RANGE

where APNNAME is the name that you should have received from the getAPNList LTErf command. The rest of the arguments are mandatory, and should be used for updating the existing IP configuration for the APN used. By default, NITOS is using the "default" APN, with addresses from the 10.0.3.0/24 range.

Updating subscriber information

The subscribers are assigned to a subscriber group, and hold their own subscriber information (like IMSIs, etc.). In order to retrieve the available subscriber profiles, you can send the following command at the nitlab3 console:

wget -qO- http://lterf:5054/lterf/epc/set?function=getSubscriberProfileList | xml_pp

The XML doc returned by the service, should contain all the configured Subscriber Profiles at the SiRRAN EPC network. By default, all the NITOS clients are configured to use the "NITOS_SS" subscriber profile.

You can retrieve more information about this profile with the following command:

wget -qO- "http://lterf:5054/lterf/epc/set?function=getSubscriberProfile&args=NITOS_SS" | xml_pp

The command will return you the configuration set for this profile; the name of the profile, the APN associated with it, the default QCI for the subscribers, the default allocation and retention policy for the subscribers on this profile, and the aggregate UL and DL bandwidth to be used by them (in bps).

You can either create a new subscriber profile or update an existing one as follows:

wget -qO- "http://lterf:5054/lterf/epc/set?function=addSubscriberProfile&args=NEW_SS,APN_to_be_used,5,1,100000000,100000000" | xml_pp

This command will create the Subscriber Profile NEW_SS, associated with the APN_to_be_used, and all the subscribers that will be added will use as default QCI 5 and ARP 1. The aggregate UL and DL bandwidth for all the subscribers will be 100Mbps.

You can update an existing profile as follows:

wget -qO- "http://lterf:5054/lterf/epc/set?function=addSubscriberProfile&args=EXISTING_SS,APN_to_be_used,QCI_to_be_used,ARP_to_be_used,Aggr_UL,Aggr_DL" | xml_pp

You can always delete an existing subscriber profile with the following command:

wget -qO- "http://lterf:5054/lterf/epc/set?function=deleteSubscriberProfile&args=Subscriber_Profile_Name"

Now that the subscriber profiles are all set, you can further configure the subscribers in NITOS. By default, the subscribers configured in NITOS are complying to the following rules:

This configuration is subject to change. You should verify that the nodes that you want to connect to the LTE network have these IMSIs. To do so, open a terminal on the node and use minicom to connect to /dev/ttyUSB0. From there, type the following command:

root@nodeXX# minicom -D /dev/ttyUSB0
AT+CIMI

The last command reports you the IMSI that each node has.

In order to get all the subscribers configured for the LTE network, you can send the following command from the nitlab3 console:

wget -qO- "http://lterf:5054/lterf/epc/set?function=getSubscriberList" | xml_pp

The command returns an XML doc containing the subscriber configuration in the HSS. You can retrieve more information about a specific subscriber with the following command:

wget -qO- "http://lterf:5054/lterf/epc/set?function=getSubscriber&args=IMSI" | xml_pp

where IMSI is the IMSI of the client you want to retrieve the configuration information. The XML contains some valuable information: 1. the client's IMSI, 2. the MSISDN (currently not used by the EPC so this should be always NULL), 3. the K-code used by the SIM card (for NITOS, this should be always 000102030405060708090A0B0C0D0E0F), 4. the OP Code (if set to null/nil, the subscriber uses the global OP Code set to EPC), 5. the subscriber Status (Enabled/Disabled), 6. the Subscriber Profile that this UE is assigned to, 7. the method for allocating IP addresses (Static/Dynamic), 8. the IP address that is assigned to it.

You can update this information to use a new IP address from a different subnet (along with the APN configuration and subscriber profile configurations) with the following commands:

wget -qO- "http://lterf:5054/lterf/epc/set?function=updateSubscriber&args=IMSI,nil,000102030405060708090A0B0C0D0E0F,'',Enabled,Subscriber_Profile,Static,IP_Address" | xml_pp

 If the subscriber you want to alter is not existing, you can add it by with the following command:

wget -qO- "http://lterf:5054/lterf/epc/set?function=addSubscriber&args=IMSI,nil,000102030405060708090A0B0C0D0E0F,'',Enabled,Subscriber_Profile,Static,IP_Address" | xml_pp

 And you can delete an existing subscriber with the following command:

wget -qO- "http://lterf:5054/lterf/epc/set?function=deleteSubscriber&args=IMSI"

Saving/Loading EPC changes

In case of extended changes, the LTErf service is allowing you to save/load the configuration of the EPC network/base station.

You can check the names of the configurations stored with the following command:

wget -qO- "http://lterf:5054/lterf/epc/config/list" | xml_pp

The names inside the XML elements are the names for the existing configurations for the EPC network. If you switch "epc" with "bs" in the http command, you will get the respective service for the base station components.

You can save your EPC configuration with the following command:

wget -qO- "http://lterf:5054/lterf/epc/config/save?name=MYNAME" | xml_pp

You can load it using the following command:

wget -qO- "http://lterf:5054/lterf/epc/config/load?name=MYNAME" | xml_pp

After loading, you will need to restart the EPC for the changes to take effect.

You can delete your configuration using the following command:

wget -qO- "http://lterf:5054/lterf/epc/config/delete?name=MYNAME.config" | xml_pp

(NOTE: .config is needed at the end of the configuration name for deleting it)

NOTE: Configurations which are over two month old can be deleted without notice. If you want to keep your configurations saved, contact the NITOS administrators