1. 4 | Usage and Traffic Modeling

2. Information Requirements for Usage Modeling
20335B
Information Requirements for Usage Modeling
05: Usage and Traffic Modeling
These include:
Usage scenarios
Usage models
Personas
Capturing data for usage models:
How many site locations are there?
How many users are at each site location?
How many users will always be remote?
What are the future growth estimates?
What sort of WAN technology/topology is deployed?
What is your overall WAN link speed?
What is the maximum/current available bandwidth for Skype for Business traffic per WAN link?
Predefined usage models

3. Using Personas in Usage Modeling
20335B
Using Personas in Usage Modeling
05: Usage and Traffic Modeling
Personas:
Represent the behavior of classes of users present in a customer’s environment.
Up to 10 personas in the tool.
They are typically independent of location.
Persona characteristics include:
Utilization of Skype for Business modalities as defined in usage models: none, low, medium, high:
They can be job-related (for example, ”our sales reps make plenty of PSTN voice calls”)
They can be related to administrative policy (for example, “video calls are not allowed for vendors in our organization”)
Percentage of users working remotely: 0% – 100%
Others factors related to administrative policies or users behavior.

4. Validating Personas and Usage Models
20335B
Validating Personas and Usage Models
05: Usage and Traffic Modeling
Information to evaluate includes:
The number of PBXs implemented
The number of PSTN channels provisioned
The number of any intersite tie connections between PBXs, or whether intersite calls are made through the PSTN
The number of users at each location
Call data records (CDRs) for PSTN traffic usage
Usage statistics, such as the maximum number of concurrent calls during the busy hour:
Total number and usage of PSTN channels at each site
Trunk usage for intersite connections
Other Locations
PSTN
PBX
Peer Channels
PSTN Channels

5. Collecting Data to Validate Models for Estimating Call Flow
20335B
Collecting Data to Validate Models for Estimating Call Flow
05: Usage and Traffic Modeling
This includes:
Maximum number of conferencing ports used.
Average maximum number of concurrent conferences.
Including the number of participants when that maximum occurs.
Average meeting size.
Average meeting duration.
Total minutes of conferencing used per day and per month.

6. Lync Bandwidth Calculator Usage Models
05: Usage and Traffic Modeling
Maximum concurrency of x% of the user base using instant messaging and presence
Maximum concurrency of x% of the user base using peer-to-peer audio
Maximum concurrency of x% of the user base using peer-to-peer video
Maximum concurrency of x% of the user base using audio conferencing
Maximum concurrency of x% of the user base using video conferencing
Maximum concurrency of x% of the user base using desktop sharing
Maximum concurrency of x% of the user base using PSTN audio
Maximum concurrency of x% of the user base working remotely

7. Microsoft Skype for Business Server 2015 Planning Tool
05: Usage and Traffic Modeling
Show the students what the Planning Tool looks like by referring to the image on the slide.
You navigate the Microsoft Skype for Business Server 2015 Planning Tool by using a combination of a toolbar, page-specific buttons and links, and context-specific panes.
The context-specific panes provide design information for planning and capacity that is relevant to the selection options on a specific page.
Note* 1) Bandwidth Calculator is being updated for Skype for Business, in this Module we will be using Lync Bandwidth Calculator as a reference
2) Skype for Business Server planning tool is in development however Lync 2013 planning tool can be used for this Module

8. Call Flow Scenarios RDP Bandwidth Estimations Screen size Acceptable
05: Usage and Traffic Modeling
RDP Bandwidth Estimations
Screen size
Acceptable
Optimal
1280x800
384 Kbps
1.5 Mbps
1440x900
512 Kbps
2 Mbps
1680x1050
768 Kbps
2.75 Mbps
1920x1200
1 Mbps
3.5 Mbps
Note: Sharing in the Microsoft PowerPoint presentation graphics program is accomplished by using a different method for desktop sharing. Older versions of Skype for Business use a built-in PowerPoint file viewer, or, for web presentations, the file is converted into a dynamic HTML stream that requires the Microsoft Silverlight browser plug-in.
To improve this experience for Skype for Business Server 2015, an Office Web Application Server handles PowerPoint presentations by using dynamic HTML and JavaScript.

9. Types of Skype for Business User-Generated Traffic
05: Usage and Traffic Modeling
These include:
Primary focus:
Peer-to-peer audio
Multiparty audio
Secondary focus:
Peer-to-peer video
Multiparty video
PSTN audio
Partially (only in modeling):
SIP signaling (includes presence)
Instant messaging
Desktop/application sharing
Transfer files
Discuss the different types of Skype for Business user-generated traffic.

10. Network Bandwidth Requirements for Skype for Business 2015
05: Usage and Traffic Modeling
Modality
Description
Maximum bandwidth
Typical bandwidth
IM, presence, and signaling
Nonmedia elements
2 Kbps
1.6 Kbps
Voice
Default = Silk Wideband
69 Kbps
44 Kbps
Conference voice
Default = G.722
100.6 Kbps
46.1 Kbps
Video – small
Uses H.264 at 320x180
250 Kbps
200 Kbps
Video – medium
Uses H.264 at 640x480
800 Kbps
640 Kbps
Video – high
Uses H.264 at 1280x1080
4 Mbps
3.2 Mbps

11. 20335B
Audio Codec Bandwidth
05: Usage and Traffic Modeling

12. Required bandwidth depends on: Resolution Quality Frame rate
Video Codec Bandwidth
05: Usage and Traffic Modeling
Required bandwidth depends on:
Resolution
Quality
Frame rate
There are three bit rates for each resolution:
Maximum payload bit rate
Minimum payload bit rate
Typical bit rate

13. Video Resolution Bandwidth
05: Usage and Traffic Modeling
Video codec
Resolution and aspect ratio
Maximum video payload bit rate (Kbps)
Minimum video payload bit rate (Kbps)
Typical bit rate (Kbps)
H.264
320x180 (16:9)
212x160 (4:3)
250 15
200
H.264/RTVideo
424x240 (16:9))
320x240 (4:3
350
100
280
480x270 (16:9)
424x320 (4:3)
450
640x360 (16:9)
640x480 (4:3)
800
300
640
848x480 (16:9)
1500
400
1200
960x540 (16:9)
2000
500
1600
1280x720 (16:9)
2500
700
1920x1080 (16:9)
4000
3200
960x144 (20:3)
1280x192 (20:3)
1000
1920x288 (20:3)

14. Endpoints Endpoints do not stream audio or video packets continuously.
20335B
Endpoints
05: Usage and Traffic Modeling
Endpoints do not stream audio or video packets continuously.
Scenarios:
Peer-to-peer:
Endpoints send audio streams only when users speak.
Both participants receive audio streams.
Both endpoints send and receive video streams during the entire call if video is used.
Video scenes with little or no movement may temporarily have a low actual bit rate because the video codec skips encoding regions of the video with no changes.
Conferencing:
All participants receive audio streams.
All participants can receive up to five video streams and 1 panoramic video stream if video is used.

15. Lync Bandwidth Calculation Overview
05: Usage and Traffic Modeling
…and Grey = formulas or results (locked cells)
Green
Yellow
Red
Do not forget that:
Green = Required user entry
Yellow = Can be modified from the defaults
Red = Cannot be modified

16. Defining Personas in the Lync Bandwidth Calculator
05: Usage and Traffic Modeling
Site users:
Must be grouped based on ”Personas”.
Up to three persona types can be selected individually in each site.

17. Sites 20335B 05: Usage and Traffic Modeling
The WAN link columns are discussed in the next topic.

18. Central Sites Central sites:
20335B
Central Sites
05: Usage and Traffic Modeling
Central sites:
Where Skype for Business Front-End pools will be located:
If the Skype for Business deployment has mulitiple distributed Skype for Business Front-End pools, then enter multiple Central sites (unless all Front-End pools are in the same network site).
WAN links must be defined:
“WAN link speed” is the total size of the connection to the MPLS WAN cloud.
“WAN link BW Allocated to RTC traffic” is how much bandwidth the customer wants to allow for Skype for Business RTC:
Typically this should be assumed as 30% of WAN link (industry-standard for RTC traffic on the WAN links)
Global “Red flag” threshold is set to this value, but it can be defined to a level expected by the customer

19. Branch Sites Branch sites:
05: Usage and Traffic Modeling
Branch sites:
Are sites with Skype for Business users only:
Each Branch site must be associated with a Central site.
If many similar branches, one row can summarize them.
Might have local PSTN gateways:
If so, then select ”Local PSTN Breakout” = Yes (with Media Bypass on, or when Mediation server is also in the branch, adjacant to the voice gateway).
If not, than set “Use G711 for PSTN Calls over WAN?” correctly.

20. Bandwidth Modeling Results for Sites
05: Usage and Traffic Modeling
These include:
Individual results – WAN link consumption split per modality:
Inter-site traffic only.
Traffic of users located in this site only.
Traffic of remote users considered as necessary.

21. Aggregated Results: Table 1
05: Usage and Traffic Modeling
Table 1: WAN traffic aggregated in each Central site:
Split by Skype for Business modality.
Totals (WAN and Skype for Business RTC) with limit/threshold checks.
Audio/video/conferencing total.

22. Aggregated Results: Table 2
05: Usage and Traffic Modeling
Table 2: Internet traffic of remote users, aggregated in each Internet site:
Split by Skype for Business modality.
Totals with limit/threshold checks.

23. Graphical Results These include:
20335B
Graphical Results
05: Usage and Traffic Modeling
These include:
Skype for Business RTC bandwidth requirements and availability:
Helps to quickly identify which sites might be lacking bandwidth for Skype for Business.
Can choose which sites are to be graphed.
Focus on Skype for Business RTC bandwidth requirements and availability:
Helps to quickly identify which sites might be lacking bandwidth for Skype for Business RTC traffic.
Useful for creating executive-level reports in a network assessment final report.
You can choose the results from the sites that are to be graphed.

24. Deployment Readiness This information includes:
20335B
Deployment Readiness
05: Usage and Traffic Modeling
This information includes:
A summary of sites that may require a WAN upgrade before they can carry the estimated volume of Skype for Business RTC traffic.
Focus on Skype for Business RTC bandwidth requirements and availability:
Overall look at the whole Skype for Business deployment.
Useful for creating executive-level reports in a network assessment final report.
RTC with or without video.

25. Define QoS Traffic Classification
20335B
Define QoS Traffic Classification
05: Usage and Traffic Modeling
Use the Lync Bandwidth Calculator to:
Define Quality of Service (QoS) traffic classification
An example of an advanced task.
RESULT

26. To determine the number of Erlangs:
Erlang Calculator
05: Usage and Traffic Modeling
Calculations:
One Erlang equals one continuous call for seconds (the number of seconds in one hour).
To determine the number of Erlangs:
Multiply the number of calls during the busy hour (B) times the average call length in seconds (L), and then divide by 3600: Erlangs = (B*L)/3600

27. Traffic Simulation Tools
20335B
Traffic Simulation Tools
06: Performing Traffic Simulations
These tools:
Generate real audio and video RTP/RTCP traffic
Centrally manage the probes.
Mark traffic with Quality of Service (QoS) markings.
Collect and graph the five baseline network characteristics.
Support all five baseline characteristics:
One-way network delay
Average jitter
Maximum jitter
Average packet loss
Burst packet loss (peak consecutive packets lost)

28. Simulating Bandwidth Requirements
06: Performing Traffic Simulations
A well-designed traffic simulation sampling scenario enables you to:
Determine if congestion patterns develop
Determine if the QoS policies are effective and applied correctly
Gauge network response during congestion periods:
For example, dropped packets, delay and jitter effects, and so on

29. Identifying Sites for Traffic Simulation
20335B
Identifying Sites for Traffic Simulation
06: Performing Traffic Simulations
Take the following into consideration:
There is always a limit:
The standard network assessment is scoped for up to 20 sites.
Make sure to test in representative sites.
Do not test for insufficient bandwidth if this is already known.
Central sites should always host a simulation endpoint.
Focus on the possible weak parts of the network:
Where the Modeling phase revealed the link bandwidth might be barely enough.
Connections traveling between continents that are prone to packet loss and delay.
Connections with expected high utilization (users talk often).
Where there is existing knowledge of poor quality WAN links.
User input or preferences other than technical nature:
For example: ”That is the site where the chief executive officer (CEO) is based”

30. Skype for Business Server Real-Time Scenarios to Be Simulated
06: Performing Traffic Simulations
For these:
Peer traffic should be evenly distributed between other remote location probes:
Audio traffic volume
Video traffic volume
Conference traffic should be between the remote probe and the data center probe:
PSTN traffic should be between the remote probe and the data center probe:

31. Preparing for Traffic Simulation
20335B
Preparing for Traffic Simulation
06: Performing Traffic Simulations
To do so:
Verify site selection
Decide on traffic distribution and allocation (flows and amount of traffic to simulate)

32. Traffic Simulation Best Practices
06: Performing Traffic Simulations
It is important to:
Verify site selection based on anticipated Skype for Business Server real-time services
Decide the level of traffic distribution and allocation required
Know key sites and bandwidth for traffic scenarios
Keep the list of sites to 20 or less
Test representative sites that will use Skype for Business Server RTC services
Focus on potential network weak points
Determine potential packet loss and delay for connections
Inquire about existing organizational knowledge regarding poor quality
Consider other site selection input other than technical
Consider traffic distribution and allocation between sites
Perform initial modeling with the Skype for Business Bandwidth Calculator

33. Skype for Business Server 2015 Stress and Performance Tool Package
06: Performing Traffic Simulations
The Skype for Business Server 2015 Stress and Performance Tool (LSS) simulates the following types of user loads:
Instant messaging (IM) and presence
Audio/Video/Multi-View conferencing
Application sharing
Voice over IP (VoIP), including public switched telephone network (PSTN) simulation
Web Access Client conferencing
Conferencing Attendant
Response Groups
Distribution list expansion
Address book download and address book query
E911 calls and Location Profile