(First of all, I'm sorry for this wall of text. I don't know how to make it any shorter without losing important information. I originally wanted to use the chat room for this, like we do on serverfault for these kind of questions, but there is nobody in the network engineering room).
We're a corporation with several daughter companies, where we have a rather large managed IP-VPN with about 70 different locations, varying from 2Mbps SHDSL to 100Mbps fiber. The IP-VPN carries multiple VPNs (or tunnels to be exact).
The priority of traffic is this, from a management and design standpoint:
- VoIP (Avaya and Lync)
- Video (Lync)
- Internal services (fileservers, Active Directory, intranet etc)
- Non-prioritized internal services (proxy servers for internet usage, windows update services, system center configuration management, antivirus update proxies etc)
- The not matched traffic (internet)
VoIP is only used at certain offices, where there is a low amount of users. The biggest remote office that use VoIP right now has a 4mbps SHDSL with 5 employees and 5 avaya IP phones running the G.711 ALAW 64K codec. This should never bring the voip data traffic up to more than 320kbps. I've verified that the phones use DSCP 46 for audio, and it's therefore correctly matched as EF (see config below). The signaling however is matched as DSCP 24, which I'm not sure if our QoS profile picks up..
All remote locations use RDP against several RDS farms at our HQ (2x100Mbit fiber). The bandwidth used for RDP is not so easy to figure out, since it basically uses everything it gets. We do have certain limitations set to make sure that it's not too resource hungry, but that is probably out of scope for this site. We do have some rather severe problems with RDP lately (https://serverfault.com/questions/515809/mouse-cursor-jumps-around-when-using-rdp), which is why I'm posting this on network engineering.
Lync uses DSCP 46 for audio and DSCP 34 for video. Internal services and non-prioritized internal services are just matched by subnets, and everything else is just match any.
Here is a copy of the latest QoS config revision, which I have modified slightly to hide certain names and IP addresses:
! class-map match-any INTERNAL-PRI match access-group name CUST-INT-PRI match access-group name CUST-DMZ class-map match-any INTERNAL-NOPRI match access-group name CUST-INT-NOPRI class-map match-any REMOTEDESKTOP match access-group name RDP class-map match-any ALL match any class-map match-any NETWORK match ip precedence 6 match ip precedence 7 class-map match-any EF match ip dscp ef match ip dscp cs5 class-map match-any AF-HIGH match ip dscp af41 match ip dscp cs4 class-map match-any AF-MEDHI match ip dscp af31 match ip dscp cs3 class-map match-any AF-MEDIUM match ip dscp af21 match ip dscp cs2 class-map match-any AF-LOW match ip dscp af11 match ip dscp cs1 class-map match-any BE match ip dscp default ! ! policy-map setTos class EF class REMOTEDESKTOP set ip dscp af31 class INTERNAL-PRI set ip dscp af21 class INTERNAL-NONPRI set ip dscp af11 class class-default set ip dscp default policy-map useTos class EF priority percent 10 class AF-HIGH bandwidth remaining percent 35 class AF-MEDHI bandwidth remaining percent 25 class AF-LOW bandwidth remaining percent 20 class BE bandwidth remaining percent 10 class NETWORK policy-map QOS class ALL shape average 4096000 service-policy useTos ! ! ip access-list standard CUST-DMZ permit 18.104.22.168 0.0.0.255 ! ip access-list standard CUST-INT-PRI permit 10.50.0.0 0.0.0.255 permit 10.51.0.0 0.0.0.255 ! ip access-list standard CUST-INT-NOPRI permit 10.50.10.0 0.0.0.255 permit 10.51.10.0 0.0.0.255 ! ip access-list extended RDP permit tcp any eq 3389 any permit tcp any any eq 3389 !
As you can see, it's a rather large QoS configuration. Note that we did not create this config our selves, it was all done by a previous employee at our IP-VPN provider. Note also that the shape value is changed according to what kind of connection it is (2mbps, 4mbps, 8mbps and 10mbps).
By now you're probably wondering - What's the question here? Here goes..
- Like I mentioned earlier, we are drowning in complaints from RDP users about lag/user input not being recognized. Are we not prioritizing it correctly? Is it possible to make sure that RDP gets a minimum amount of packet loss, latency and jitter, but still being restricted in bandwith?
- I'm not seeing any mention of queues in this config. I've read some Microsoft documentation, and they recommend to use priority queue on VoIP and WRED on video. How do I make this happen?
- As the config shows, none of the AF classings use medium or high drop. What kind of services are safe to drop? RDP, video and voip does not work well with drops..
- Are the bandwith percentages in order? It sums up to 100% usage
Any other suggestion(s) are welcome, as I'm desperate to get this sorted out. If you think it's too much to answer on a Q&A site I'll just bite the dust and hire a consultant from our Cisco Gold partner, which is financially OK - I just want to learn this if I can.