LTE: When static and dynamic IP addresses are assigned to UE in LTE attach procedure ?

Question

Is it network choice or user choice to assign static IP address ? I want to know when these decisions are taken and which element of the network takes these types of decision ?

Answer 1

Hello Vimal, as far as I know assignment of static or dynamic IP is part of subscription. Long time back, I worked in S6a interface i.e. the interface between MME and HSS. When an UE does attach to MME, it fetches APN subscription data from HSS by using the Update Location Answer message. The Update Location Answer message carries an AVP "Subscription-Data" which in turn carries "APN-Configuration-Profile".

If you go into depth of this AVP, you will find "Served-Party-IP-Address " . If user is subscribed for static IP address then this AVP will be present and network will assign the subscribed IP address.
Usually, when an device want to become server, it prefers to have static ip address. Please correct me if I am wrong.

Comments

Thanks Harshita to share these details.

Answer 2

Hello,
When MS has to use a static ip the IP is configured in HLR/HSS against the PDP subscription data. If MS uses static ip then only network initiated PDP context activation procedure is possible.
Other than this there are other advantages also , e.g an ip level firewall can also used for an IMSI , if ip of IMSI is always fixed.
Thanks