QoS Bandwidth Settings on VLAN Interfaces behind RED 50

Question

Hi, 
 just a general question concerning Bandwidth settings for RED interfaces behind a RED 50 running in standard unified mode. 
 
 RED 50 in Branch office is connected via 100 MBit Line to HQ. 
 3 VLAN interfaces on RED. 
 
 I want to configure QoS for some VOIP DSCP values for traffic going over the red. 
 Do I have to split the total available bandwidth (of 100 MBit/s) to the 3 red-interfaces? Or should I define the same maximal possible value (100) to each of them? 
 
 Thanks 
 Philipp

BAlfson · Answer

Hi Philipp, 
 First, check the Intrusion Prevention log (be sure to read #1 in Rulz) . It's not unlikely that that's your problem. 
 Bandwidth Pools only limit other traffic when necessary to provide guaranteed bandwidth to desired traffic. Download Throttling rules put hard limits on other traffic so that the desired traffic has the remainder. I would start with Bandwidth Pools only. If you still have jitter, then add Download Throttling rules. 
 In the Bandwidth Pools, you will want to guarantee 100kbits multiplied by the number of phones on each VLAN. 
 If you need Download Throttling, make two rules for each VoIP interface and one for VLAN 11. Yes, you will need to split the link speed between the three interfaces. First, one "limiting" VoIP traffic to 1000000 kbits (this is, in effect, a "no limit" exception to the following rule). Follow that by a rule limiting all traffic to the portion of 100Mbits you want to allocate to that VLAN subtracting 100kbits for the number of simultaneous calls you expect on that VLAN - you will likely want to play with your estimate. 
 Gl&uuml;ck gehabt? 
 Cheers - Bob