I have a query on the IMS.
What options does the various PGW/GGSN vendors offer when load balancing the traffic to an array of P-CSCFs?
GSMA/3GPP have not standardized anything in particular.
Any vendors have provided anything extra than the traditional round-robin model?
Does anyone have dynamic distribution based on the current weight (active IPSec tunnels in a P-CSCF)?
In Huawei PGW, we have option of assigning Primary Secondary.
Second option they go with weight option between active / active P-CSCFs.
Like 80-20 which is configurable as per capacity.
Note: This is for /// EPG(PGW).
Did you check S CSCF which has the routing?
The Serving Call Session Control Function (S-CSCF) is the main node in the IP Multimedia Subsystem (IMS) signaling plane.
The S-CSCF, which acts as both a SIP server and registrar, is assigned to serve end users for the duration of their connection to the IMS network.
The assignment of users to an S- CSCF is performed by the Interrogating CSCF (I-CSCF) during the user SIP agent registration.
The I-CSCF assigns the S-CSCF based on the capabilities required in the user profile.
You have the option of setting P-CSCF discovery either in the PCO of the PGW, or on the SIM.
If you set it on the SIM you can use DNS-SRV based load balancing, however most commonly it’s the static list in the PCO.