Difference between local break out and home routed traffic in lte network ?

Question

When the PGW is changed, there is a possibility of a change of IP address. The UE may request for the assignment of the same IP in the new nw as well, but allocation of the same is not guaranteed.
In this case, it is imminent that the UE will experience a glitch in service. While the same is not true with Home-routed configuration(as PGW doesnt change). Isnt this a limitation?

Answer 1

LTE roaming architecture supports two options through which UE can access external world. When an UE attaches to visitor network, MME at visited network fetches UE subscription profile from HSS of UE's home network.

Visited network MME establishes session with SGW of its own network and may establish session with PGW of UE's home network (in case of home routed traffic) or PGW of visited network (in case of local breakout).

In case of home routed traffic, policy and charging enforcement rules are imposed at home network PGW but for local breakout case, V-PCRF comes into picture.

Answer 2

If the user in visited network (In roaming scenario) then, it is not required that the media path use the home networ's entities or home network resources. So media can flow to visited network of caller to the home network of callee So that resource of home network of caller will not be used.
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To achive this two things comes in picture..
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1) TRF (Transit and roaming functionality) : A new entity called the Transit & Routing Function (TRF) is introduced, which brings the SIP signals back from the network where the caller is currently connected to the home network performing call processing.
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2) Local Breakout : It is a key feature of LTE. It enables visitor networks to breakout internet sessions into home network, instead of routing back to Home networks.

Comments

can  you explain about advantage and disadvantage of local breakout? how visiter networks can breakout internet session into home network? what is breakout internet session?