GTP¶

GTP is a protocol used to carry user traffic between a radio access mobile network and an external core network, usually the Internet. For that purpose, GTP-U tunnels are created for each user session, and attached to a GTP interface.

Note

GTP-U tunnels are not meant to be created through configuration. They are maintained by the PFCP service.

Setting up a GTP interface¶

To configure a GTP interface, enter the context interface with the type gtp from the target VRF.

vsr> edit running
vsr running config# vrf main
vsr running vrf main# interface gtp gtp0
vsr running gtp gtp0# commit

Here is the state of the interface after the configuration is applied:

vsr running vrf main# interface gtp gtp0
vsr running gtp gtp0# show state
gtp gtp0
    mtu 1500
    promiscuous false
    enabled true
    oper-status UP
    counters
        in-octets 0
        in-unicast-pkts 0
        in-discards 0
        in-errors 0
        out-octets 0
        out-unicast-pkts 0
        out-discards 0
        out-errors 0
        ..
    ..

The same configuration can be made using this NETCONF XML configuration:

vsr running gtp gtp0# show config xml absolute
<config xmlns="urn:6wind:vrouter">
  <vrf>
    <name>main</name>
    <interface xmlns="urn:6wind:vrouter/interface">
      <gtp xmlns="urn:6wind:vrouter/gtp">
       <name>gtp0</name>
       <enabled>true</enabled>
      </gtp>
    </interface>
  </vrf>
</config>

Listing GTP-U tunnels¶

To retrieve established GTP-U tunnels:

vsr> show gtp tunnels
Interface Role    Remote endpoint Remote TEID Local TEID     UE/MS address Rx packets Rx bytes Tx packets Tx bytes
========= ====    =============== =========== ==========     ============= ========== ======== ========== ========
gtp0      relay        10.100.0.1           2          6                            0        0          0        0
gtp0      relay        10.125.0.2           1          1                            5      640          5      640
gtp0      relay        10.125.0.2           5          5                            0        0          0        0
gtp0      relay        10.100.0.1           1          2                            5      640          5      640
gtp0      gateway      10.125.0.2           4          3         10.60.0.2          0        0          0        0
                                                         fd9d:b682:cb83::2
gtp0      gateway      10.125.0.2           2          1         10.60.0.1          5      420          5      420
                                                         fd9d:b682:cb83::1

To avoid flooding the terminal, output is limited to 1000 tunnels by default. This limit can be disabled or modified as necessary:

vsr> show gtp tunnels limit 2
Interface Role  Remote endpoint Remote TEID Local TEID UE/MS address Rx packets Rx bytes Tx packets Tx bytes
========= ====  =============== =========== ========== ============= ========== ======== ========== ========
gtp0      relay      10.100.0.1           2          6                        0        0          0        0
gtp0      relay      10.125.0.2           1          1                        5      640          5      640
Query limit reached. Increase it to display the remaining tunnels.

Output can be further restricted to tunnels matching at least one UE/MS address from a list:

vsr> show gtp tunnels ue-address 10.60.0.1 ue-address fd9d:b682:cb83::2
Interface Role    Remote endpoint Remote TEID Local TEID     UE/MS address Rx packets Rx bytes Tx packets Tx bytes
========= ====    =============== =========== ==========     ============= ========== ======== ========== ========
gtp0      gateway      10.125.0.2           4          3         10.60.0.2          0        0          0        0
                                                         fd9d:b682:cb83::2
gtp0      gateway      10.125.0.2           2          1         10.60.0.1          5      420          5      420
                                                         fd9d:b682:cb83::1

Note

Mainly applies to tunnels with a gateway role since relay tunnels do not carry this information.

Filtering by role is also supported:

vsr> show gtp tunnels role gateway limit 1
Interface Role    Remote endpoint Remote TEID Local TEID     UE/MS address Rx packets Rx bytes Tx packets Tx bytes
========= ====    =============== =========== ==========     ============= ========== ======== ========== ========
gtp0      gateway      10.125.0.2           4          3         10.60.0.2          0        0          0        0
                                                         fd9d:b682:cb83::2
Query limit reached. Increase it to display the remaining tunnels.