There is no difference, it's a preference to either use it at the GW level or Device pool.
As to local route group it is used for local route group routing where the device pool assigned to devices such as phones controls which route to take. Basically simplifies amount of route patterns required. Take a look at SRND for more details.
IntroductionCUCM Routing RulesDial String implementation PolicyCUCM Routing LogicSIP URI Call Routing Analysis+++ Case Study: 1 ++++++ Case Study: 2 +++Conclusion
Over the last few months, I have had the privilege of working on SI...
Are you getting this error “Installer User Interface Mode Not Supported. The installer cannot run in this UI mode. To specify the interface mode, use the -i command-line option, followed by the UI mode identifier. The value UI mode identifiers...