1. UE registered and PDU established.
2. PCF does not receive Heartbeat.
- PCF De-registered state.
- Since PDU is established, SMF should not remove NF instance
3. PCF re-registered.
- HERE, WE NEED TO INCREASE NF REFERENCE COUNT.
Otherwise, NF instance will be removed if PCF is de-registered state
4. UE sends PDU release request.
5. Because SMF knows PCF NF instance, SMF can send PCF delete
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
As per 3GPP TS 23.401 version 15.12.0, section 5.3.1.2.2
The PDN GW allocates a globally unique /64
IPv6 prefix via Router Advertisement to a given UE.
After the UE has received the Router Advertisement message, it
constructs a full IPv6 address via IPv6 Stateless Address
autoconfiguration in accordance with RFC 4862 using the interface
identifier assigned by PDN GW.
For stateless address autoconfiguration however, the UE can
choose any interface identifier to generate IPv6 addresses, other
than link-local, without involving the network.
And, from section 5.3.1.1, Both EPS network elements and UE shall
support the following mechanisms:
/64 IPv6 prefix allocation via IPv6 Stateless Address
autoconfiguration according to RFC 4862, if IPv6 is
supported.
* [SMF] Gn: Avoid assert crash if no PDP resources available
* [SMF] Gn: Rearrange IE handling order in CreatePDPContextRequest
Let's handle the GTPC remote addr + TEID first, since those should be
used in the CreatePDPContextResponse ideally if available.
Let's then handle parsing of all IEs not related to bearers/UserPlane,
then those missing, and finally do all the IP resource allocation.
* 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.
"
* [SMF] typo fixes in commented code
* [SMF] Fix early err return handling UpdatePDPContextRequest
* [SMF] UpdatePDPContext: forward update of remote TEID+IPaddr to UPF
Updating the remote GTP-U IP address and/or TEID on the GGSN is a common
practice, used for instance by an SGSN in a UTRAN network to connect an
HNB(GW) to exchange GTP-U directly with the GGSN. It is also used in
general when doing handovers.
When receiving a UpdatePDPContext with the new address, we need to
forward the update to the UPF so that it takes it into account when
forwarding packets.
This patch only implements updating the information towards the UPF when
GTPv1C is used. Similar approach for GTPv2C (upon receival of Modify
Bearer Request) is still unimplemented.
Related: https://github.com/open5gs/open5gs/issues/1367
In the event we have 2 local IP addresses available for use, put the one
having same IP version in "GGSN Address *" IE, and the one with the
other IP version in "Alternative GGSN Address *" IE.
Same fix was applied recently to CreatePDPContextResponse.
TS 29.060 sections 7.3.4 and 7.3.6 specify the possible cause values for
UpdatePdpContextResponse and DeletePdpContextResponse.
Together with section 8.2, it becomes clear that 'Non-existent' cause
should be sent instead of 'Context not found' one in those cases.
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.
In the event we have 2 local IP addresses available for use, put the one
having same IP version in "GGSN Address *" IE, and the one with the
other IP version in "Alternative GGSN Address *" IE.
* [CORE] tlv: Store mode in ogs_tlv_t
This allows specifying the format of the IE for each individual IE,
hence allowing messages containing IEs formatted in different ways.
This is needed in order to support parsing GTPv1-C, since messages
contain IEs with different structure (TLV vs TV). Hence, this is a
preparation patch to add support for parsing TVs in ogs-tlv.c/.h.
* [CORE] tlv: Support parsing msg with both TLV and TV in it
IEs of type TV are sometimes used in GTPv1-C. Current tlv parser/builder
doesn't provide with ways to parse messages which contain TV formatted
IEs. This patch adds the relevant types and ways to encode/decode them.
Furthermore, the current parser/builder allows parsing/building messages
containing the exact same format in all its IEs. A new parser function
is added which allows parsing messages of different types (TV, TLV)
mixed in the same message. In order to be able to do so, it uses the
general msg_mode passed to it in order to know the general TLV format
(in essence, the length of the Tag field, and also the length of the
Length field if applicable each IE).
Looking up the instance in the TLV description is left undone and
hadcoded to 0, since the only user so far requiring this API is GTPv1-C,
which has no instances.
* [CORE] tlv: Support repeated tag+instance parsing TLV message
In GTPv2C, repeated IEs (same tag) are easily differentiated by the
Instance byte, which provides info to match different decoded
structures. In GTPv1C though, there's no Instance byte, and we still
encounter repeated IEs (like GSN Address in Create PDP Context Request).
Hence, the TLV decoder needs to be updated to track count of IEs found
(identified by tag+instance, where instance is always 0 in GTPv1C) and
get the proper description index + offset into the decoded structure.
* [GTP]: Move GTPv2-C specifics to its own libgtp subdir
This will allow adding GTPv1-C code by the side. Most GTPv2 code is left
in this patch as "gtp" instead of renaming it to "gtp2" in order to
avoid massive changes. It can be done at a later stage if wanted.
* [GTP] Support generating GTPv1-C messages
* [SMF] Add Gn interface support
This patch introduces GTPv1C support to open5gs-smfd. With it,
open5gs-becomes a GGSN too, where SGSN can connect to, hence supporting
GERAN and UTRAN networks.
* [configs] Remove requires systemd-networkd dep from smfd service
The smf no longer has (never had?) a dependency on systemd-networkd,
and can start and remain operational without systemd-networkd
specifically running.
* [configs] Relax upf dependency on systemd-networkd
The upf relies on systemd-networkd to create the ogstun interface, but
does not communicate with it at runtime. It currently has a "Requires"
dependency specified, which means that the upf will be stopped if
systemd-networkd is ever stopped. Since the upf doesn't actually care
if systemd-networkd is later stopped after ogstun is created, it can
use the weaker "Wants" dependency type, which allows it to keep
running even if systemd-networkd were to be stopped.
Regardless, since it does rely on systemd-networkd specifically to
create the ogstun interface, it should sequence itself "After"
systemd-networkd has been started.
Since the true dependency is ogstun, not systemd-networkd, a cleaner
approach would depend on the specific tunnel device being
available. Systemd exposes this information via device units, but I'm
not sure if they are always consistently named across platforms.
* [configs] Do not require ogstun for system online
Systemd-networkd will wait for all managed interfaces to be configured
before determining the system is online. Since the ogstun and upf are
more logically an application rather than a system networking service,
don't wait for them to be configured by default.
This breaks the circular dependency between the userspace cellular
core network services and the system's network, which will allow the
cellular core network services to sequence themselves cleanly after
the system's network is up and configured.
* [configs] Sequence network-dependent units after network-online
Since open5gs targets platforms with both ifupdown (debian) and
systemd-networkd (Ubuntu) as core networking providers, this commit
sequences network-dependent core network components after the generic
network-online.target instead of one of the specific provider
targets. This allows the core network to operate correctly with both
systemd-networkd and ifupdown (networking), and fixes the issue
observed in https://github.com/open5gs/open5gs/issues/826 where some
platforms may fail to start cleanly.
Sukchan Lee
Pau Espin
ji3k54j062k7
Supreeth Herle
Matthew Johnson