OneOffice Traffic Marking & Latency
There are 3 modes of traffic available across One Office Standard/Active and Advanced:
| Class of Service |
Applications |
Traffic Targets |
|
REAL TIME
Video and Audio conversations involving real-time human interaction. |
Able to carry apps like
 IP Telephony
IP Centrex, POTS
 replacement
Videoconferencing
Multicast video
|
Latency < 50msec
Jitter < 12.5msec
Packet loss < 0.1%
|
|
BUSINESS DATA
PC to PC transmission of files and objects that need fairly prompt delivery. |
Able to carry apps like
Office and Groupware
Remote working
File and Print services
Email & Browsing
|
Latency < 200msec
Jitter < 100msec
Packet loss < 1.0%
|
Quality of Service (QoS)
The ability of the network to deliver a predetermined level of performance to an application, or group of applications. This may include guarantees for maximizing latency, jitter and packet loss.
Class of Service (CoS)
A method of grouping application traffic into classes and applying a specific (QoS) to each traffic class.
Muti-Cos behaviour on Ingress graphically shown:
There are 2 methods available for marking of traffic, by Customer and by Telecom.
| Marking |
Who / How |
Prioritization |
| By Customer |
The customers, PBX
marks VOIP [real time]
packets as they leave the
switch with a DSCP #
of 46.
The customers, Citrix
Server marks Thin Client
[Interactive] packets as
they leave the Server with
a DSCP # of 26
The rest is
Business Grade only
|
Telecom identifies
1. VOIP [46] = priority 1
2. Citrix [26] = priority 2
3. Data = zero priority |
| By Telecom Router |
Customer does nothing |
Telecom identifies at
the Router port:
Checks inbound traffic
from PBX port, marks as
[real time] and prioritises
as = 1
Checks inbound traffic
from thin client port,
marks as [Interactive]
and prioritises as = 2
The rest is
Business Grade only
|
TIPS:
It does not…
Protect traffic within the class from other traffic within the same class.
Be very careful about the traffic that you mix in the same class.
Don’t mix loss-sensitive (e.g. Citrix) with congestion causing traffic (e.g. Windows networking).
RealTime for <= 2Mbps connections on Egress
This applies to DSL or FR technologies.
RealTime can starve all other classes. This is unlikely to be a problem in practice as applications for RealTime are typically fairly symmetric. Consider carefully what goes into RealTime.
Assigning traffic to a Traffic Class
DSCP (DiffServ Code Point) is used to identify which packets go in to which traffic class.
Standard approach is that traffic is marked at source by the application or with CPE routers.
One Office does not re-mark DSCP unless explicitly requested.
One Office has the option to classify traffic and mark/re-mark it
Points to note
DSCP values for RealTime are 32 34 36 38 40 46
DSCP values for Interactive are 16 18 20 22 24 26 28 30
Everything else is carried as Business.
DSCP values 48 and 56 are reserved for internal use. Traffic marked with these values are carried as Business unless re-marked.
If the CoS profile of the VPN connection does not have a RealTime and/or Interactive component, then traffic marked for these classes may be discarded on ingress.
You can mark traffic with one of…
DSCP value 46 for RealTime
DSCP value 26 or 18 for Interactive
DSCP value 00 for Business
Classifying and marking example:
Customer is using…
VoIP, Citrix, Web based order management system, Windows file and mail server and some general Internet Web
Identify the VoIP with RTP option – mark for RealTime (46)
Identify VoIP signalling – mark for Interactive (26) [sometime not necessary]
Identify Citrix and Web server traffic – mark for Interactive (18)
Default option – mark as Business
|
PH: 09 489 5088