Tag Archives: Active Sync

Mobile phone battery drain with Kemp Loadbalancer

Recently I implemented two KEMP LM2600 at customer site (Exchange 2013 CU3 multi role servers). At the next day customers help desk got a lot of user complaints because battery life time of their mobile phones was reduced dramatically (iPhones using EAS – Exchange Active Sync)

Solution: In Network Options uncheck “Enable TCP Keepalives”

Kemp Keepalives

Kemp documentation is recommending this as well http://kemptechnologies.com/files/downloads/documentation/7.0/Configuration_Guides/Configuration_Guide-WUI.pdf

Enable TCP Keepalives
By default the TCP keepalives are enabled which improves the reliability of TCP connections that are long lived (SSH sessions). Keepalives are not usually required for normal HTTP/HTTP Services. The keepalive messages are sent from the LoadMaster to the Real Server and to the client. Therefore, if the client is on a mobile network, there may be an issue with additional data traffic.

My comment: At the end of the day I am asking why this setting is active per default? And why this can not be set for each VS – Virtual Service? Be aware that this is a global configuration and it my affect other Services / Real Servers. To be honest, this was the first time of seeing such a behavior.