this is a rather large commit that is hard to split because
it touches quite a few components.
It's a preparation patch for adding NR split bearers in the next
step.
We realized that managing RLC and PDCP bearers for both NR and LTE
in the same entity doesn't work. This is because we use the LCID
as a key for all accesses. With NR dual connectivity however we
can have the same LCID active at the same time for both LTE and NR
carriers.
The patch solves that by creating a dedicated NR instance for RLC/PDCP
in the stack. But then the question arises for UL traffic on, e.g. LCID 4
what PDCP instance the GW should use for pushing SDUs. It doesnt' know
that. And in fact it doesn't need to. It just needs to know EPS
bearer IDs. So the next change was to remove the knowledge of what
LCIDs are from the GW. Make is agnostic and only work on EPS bearer IDs.
The handling and mapping between EPS bearer IDs and LCIDs for LTE
or NR (mainly PDCP for pushing data) is done in the Stack because
it has access to both.
The NAS also has a EPS bearer map but only knows about default and
dedicated bearers. It doesn't know on which logical channels they
are transmitted.
this patch mainly modernizes the bearer creation to use smart pointers.
that allows to simplify the error handling.
ue_stack is changed to match new interface. This commit compiles
but doesn't work.
we had it returning int but had a bug in using the return value properly,
i.e. handling when -1 was returned in RLC TM.
Thinking about it more, it doesn't make sense to have a negative return
value here anyway. Either the RLC can return a PDU or not. If it can't the
returned lenght is zero.
general-purpose method for lower layers to signal protocol
failures to higher layers, i.e. RRC.
In the current case, implement a direct release of the UE (enb) or
a reestablishment (UE).
- moved paging record handling to separate class
- parallel access to pending pcch messages by phy workers based on TTI and without common lock
- asn1 pcch message packing now takes place in stack thread, to avoid real-time issues
This feature is useful in scenarios where eNB is behind a NAT and EPC on public cloud
Since eNB's GTP-U can only bind to IP address visible in it's host (usually a private IP beind a NAT), it advertises the same to UE in S1AP message
resulting in traffic from EPC to eNB (DL traffic) not able to reach eNB. This commit solves this issue by providing a means to advertise a different IP address than the one GTP-U UDP socket is bound to.
This IP is usually advertised in InitialContextSetupResponse and E-RABSetupResponse.
In order to make use of this feature, use the following parameter in enb.conf
Example:
gtp_advertise_addr = 213.61.141.82