Do transparent / split tunnels act as a DHCP server?

Question

We have some IP phones at a remote site which has limited bandwidth (currently connected to a RED50 using a standard / split tunnel) 
 
 I am trying to setup a QOS rule so the phones always get a reserved chunk of the bandwidth as the site often maxes out their internet connection which is dropping out calls (I have done this in the UTM and it works fine at the main site). 
 However due to the IP phones being a bit rubbish at the remote site they are connecting to our public facing IP of the phone system rather than it's internal IP so at the moment the QOS rules don't apply. 
 Am I right in thinking that the only way to force traffic for phone systems public IP through our local network would be to change the tunnel to Transparent/Split and then setup a rule to make the traffic for public IP of our phone system route through local network? this way the QOS rule would come into effect? 
 Am I also right in thinking that by changing over to Transparent/split this will stop the RED from acting as a DHCP server and I will have to find another way to issue IP addresses out to devices at the remote site?

sachingurung · Answer

Hi, 
 To understand RED deployment modes, please refer: https://www.sophos.com/en-us/support/knowledgebase/116573.aspx . 
 If the RED deployment mode is Standard/split, internet requests will be managed through RED. Hence, if the IP phones connect to the internet for making calls this is the perfect deployment mode. If you want the IP phones to be routed and managed through UTM, use Standard/Unified. But, this will maximize bandwidth usage over the tunnel. Hence, if you are trying to avoid extra bandwidth utilization then you should stick to the present deployed RED mode. 
 Thanks