In the past only GTPv2C was supported, and had the "gtp" generic prefix.
Later on, GTPv1C support was added, and "gtp1" prefix was used.
Let's move GTPv2C specific bits to have "gtp2" prefix too, and leave
"gtp" prefix for generic stuff among different GTP versions.
The use of the Gy interface (SMF acting as CTF towards an OCS node) is
mandated through configuration file. Default value "enable: auto" will
only make use of it in case a Diameter peer announcing support for the
Credit-Control Application is found.
Upon subscriber session creation, and after auth check over Gx, the SMF
will create a Gy session with the OCS and only after that step the SMF
will accept the session back to the subscriber.
The OCS may then grant some traffic volumes/time and ask to be notified
back with updated measurements.
In order to get the measurements, the SMF relies on PFCP URR configured
to the UPF through Session Repoort Request messages.
When closing the subscriber session, the SMF will also terminate the Gy
session at the OCS.
So far only some specifics parts of the Gy interface as well as the PFCP
side are implemented. Those should be enough to at least have
volume/time thresholds granted by the OCS, which then will be able to
track subsriber resource use.
This patch doesn't implement the OCS side of the Gy interface, that's
left as a future exercise. The interface was tested using an OCS
emulator implemented in TTCN-3 [1]
[1] https://cgit.osmocom.org/osmo-ttcn3-hacks/
TODO:
* Use an event for the report, like SMF_EVT_N4_TIMER?
* Properly set Service identifier in Gy CCR
* SMF: Properly set pkt/octet volumes in Gy CCR
** Update when receiving PFCP Modify Response.
* Figure out best way to require Gy through config file in open5gs-smfd.
* Create a new sess-sm.c which handles smf_sess_t state through
Gx+Gy+PFCP creation, modification and tear down. This way we can do
stuff in parallel, for instance Gx+Gy. It will alsoavoid duplicating
some code paths due to Gy being optional.
This commit adds required blocks in lib/diameter to be able to handle Gy
messages later in open5gs apps.
The Gy interface is mainly decribed in 3GPP TS 32.299 and 3GPP TS
32.251, which in turn refers to Diameter protcols defined in RFC4006.
This interface allows charging managment through an external OCS node.
The "Report Triggers" is sent SMF->UPF to tell in which situations a
report should be sent.
The "Usage Report Trigger" is sent UPF->SMF to indicate which situation
triggered the report.
* [PFCP] Fix trailing whitespace in message generation files
* [PFCP] message gen: Support multiple URR ID IEs in Create PDR group
* [PFCP] Support associating multiple URRs to a PDR
According to 3GPP TS 29.244:
"""
A PDR shall contain:
- zero, one or more URRs, which contains instructions related to traffic measurement and reporting.
"""
These will be further needed in PFCP in the future, as well as in other
Diameter based interfaces (such as Gy).
Let's put all implementation details in APIs so that devs don't need to
care about those details every time.
* [PFCP] Fix trailing whitespace
* [PFCP] Fix wrong endianess enc of some URR values
u32 tlvs are already converted to big endian automatically. Manually
doing so ends up in double conversion and hence in wrong endianness
being sent over the wire.
Similar issue was also fixed recently in the PFCP decoding path.
Related: https://github.com/open5gs/open5gs/issues/1349
mouse07410/asn1c#89
Found when tried to encode NGAP_CauseRadioNetwork_release_due_to_pre_emption
mouse07410/asn1c#90
Found when tried to decode messages encoded with newer schema
* Fix conversion from IPFilterRule to packet filter
As per 3GPP TS 24.008, following Packet filter component type identifier
are not supported on the LTE pre release-11 UEs:
IPv4 local address type
IPv6 remote address/prefix length type
IPv6 local address/prefix length type
And,
IPv6 remote address/prefix length type and
IPv6 local address/prefix length type shall be used when both MS and
Network support Local Address in TFTs.
This commit add logic to omit adding local address in packet filters
for compatibility with pre-release LTE 11 devices. The following parameter
could be used to toggle omit/no to omit behavior.
parameter:
no_ipv4v6_local_addr_in_packet_filter: <true/false>
* Remove logic of supporting pre-release LTE 11 devices in PCRF
According to TS 29.060 they should be added.
section 7.6:
"if it is a request for which a response has been defined, shall be sent
with a Sequence Number"
section 8.2:
"""
Sequence number flag (S) shall be set to "1"
...
For GTP-C messages not having a defined response message for a request
message, i.e. for messages Version Not Supported, RAN Information Relay
and Supported Extension Headers Notification, the Sequence Number shall
be ignored by the receiver.
"
It seems to be actually mandatory in GGSN->SGN directon, though it is
ignored in Release99 upwards. Let's hardcode it to 0 for now, should be
fine in the majority of cases.
Sukchan Lee
Pau Espin
EugeneBogush
Supreeth Herle