Selection of Roaming operators by visiting network for the purpose of directing them to one particular SGW

Question

What I know that the selection for the serving SGW is done through two main stages, the 1st stage is done through TAC values shared by the eNB's towards the MME while the 2nd stage is done through using the IMSI (MCC+MNC) of the user and according to that the DNS queries will be send to DNS server that will reply back with the serving SGW.

The logic that I am thinking of is correct? If this is the true then the MME should be able to build different tables to the different MCC/MNC's and thus, it will be dealt differently and through such tables I can configure one particular SGW to be served for some particular MCC/MNC's...

Answer 1

MME load and its performance is one of the big factor so If operator is having 2G,3G and LTE then building MCC/MNC table in MME despite of having DNS will increase the load and will surely effect MME performance.

However static routing for particular MCC/MNC can be done through MME and in many cases it is used in SGSN as well.