Capacity Planning

Capacity Planning

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The 2007 R2 product release

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The 2007 product release

Microsoft Office Communications Server 2007 R2

Capacity Planning

Topic Last Modified: 2011-01-07

The capacity planning requirements are based on the proposed user models for Office Communications Server 2007 R2. This section describes those user models, and it provides the information to help you do capacity planning for your organization.

User Models

The user models in this section provide the basis for the capacity planning requirements and recommendations described later in this section.

Office Communications Server User Model

The following table describes the user model for Office Communications Server.

Table 1. User Model for Office Communications Server

Category	Description
Client distribution	30% of clients running Office Communicator 2007 clients, including Communicator Web Access (2007 release) or Communicator Mobile (2007 release) 70% of clients running Office Communicator 2007 R2, the 2007 R2 version of Communicator Mobile, or Communicator Web Access; 100% of clients running the Live Meeting client
Remote user distribution	90% of users connecting internally 10% of users connecting through an Edge Server, and (recommended) a Director
Contact distribution	Average of 80 contacts on mobile devices Average of 50 contacts on all other devices 70% of contacts within the organization 10% of enterprise users are remote 10% of contacts are federated 10% of contacts are public IM contacts
IM sessions	2 IM sessions per user per hour 10 instant messages per session 400 byte average message size Three-person average for multiparty IM sessions

The following table describes the conferencing model used as the basis for capacity planning requirements and recommendations described later in this section.

Table 2. Conferencing Model

Category	Description
Scheduled meetings versus "Meet now" meetings	50% of each category.
Meeting concurrency	5% of users will be in conferences during working hours.
Meeting media distribution	15%: PSTN audio through a third-party audio conferencing provider, PowerPoint. 10%: PSTN audio through a third-party audio conferencing provider, application sharing. 15%: Group IM with distribution group integration. 10%: PSTN audio dial-in conferencing only. 10%: VoIP audio, PSTN dial-in conferencing, PowerPoint. 25%: VoIP audio, PSTN dial-in and video, application sharing. 5%: VoIP audio, PSTN dial-in, IM, and application sharing. 10%: VoIP audio, PSTN dial-in, video, IM.
Meeting participant distribution	In meetings where Conferencing Attendant is used with a combination of VoIP audio and PSTN dial-in audio, the ratio of VoIP users to dial-in users is 2:1. For application sharing, two types of application sharing exist: Persistent Shared Object Model (PSOM) based application sharing using the Web Conferencing Server and Remote Desktop Protocol (RDP) based application sharing based on the new Application Sharing Server. The user model assumes 80% of all ad hoc meetings use RDP-based application sharing and 20% PSOM. For scheduled meetings, the user model assumes that application sharing uses 50% PSOM and 50% RDP. Assumptions: Meetings with one participant use no RDP application sharing. For scheduled meetings with two participants, the model assumes 20% RDP application sharing. For ad hoc meetings, the model assumes 10% RDP application sharing. 25% remote access. 15% anonymous. 10% federated. 50% internal.

The following table describes the meeting content size model used as the basis for capacity planning requirements and recommendations described later in this section.

Table 3. Meeting Content Size Model

Content type	Average size	Number of instances
Multimedia Content (Flash, Windows Media player)	50 megabytes (MB)	1
PowerPoint	20 MB	2
Other Microsoft Office Document Imaging (MODI) documents	10 MB	3
Handouts	5 MB	1

Communicator Web Access Model

The Communicator Web Access usage model is based on the Office Communicator usage model, and it includes the following assumptions.

Table 4. Communicator Web Access Usage

Description	Value
Total number of users	5,000 plus 120 users doing desktop sharing
Users doing desktop sharing	120 (20 conferences)
Percentage of internal users in contact list	70%
Percentage of legacy users	30%
Average number of contacts per user	50
Maximum number of contacts per user	260
Minimum number of contacts per user	1
Hours logged on per day per user	12
Presence updates per day per user	82
Instant message conversations per day per user	12
Instant message conferences per day per user	1
Instant messages sent per user per conference (peer-to-peer)	10
Instant message sent rate	1 per minute
Instant message sessions per hour	2
Average number of participants in a multiparty session	3
Concurrent conference users at a given point of time	5% of total users
Number of presence queries per user per day	60
User searches per day	12
Contact changes per user per day	13
Percentage of concurrent desktop sharing users	2%
Maximum number of users in a desktop sharing conference	6
Duration of desktop sharing conference	1 hour

The following table lists information about the desktop sharing model.

Table 5. Desktop Sharing Model

Description	Value
Users viewing shared desktops	100
Users sharing their desktops	20
Number of conferences	20
Small conference size	2
Medium conference size	3
Large conference size	6
Largest conference size	6
Percentage of small conferences	10
Percentage of medium conferences	15
Percentage of large conferences	70
Percentage of largest conferences	5
Conference duration	1 hours
Conversations per day	24

The usage model in the previous table is based on testing on a Proliant.

Response Group Service User Model

The following table describes the proposed user model for Response Group Service used as the basis for capacity planning requirements and recommendations described later in this section.

This model assumes:

The default music-on-hold file is being used.
English is being used.

Table 6. Response Group Service User Model

Component	Per Enterprise deployment	Per Standard Edition server
Active agents (formal and informal)	1,200	1,200
Number of standard Response Groups	450	150
Number of queues used	One unique queue for each hunt group, two for the One-Level Interactive response group	One unique queue for each hunt group, two for the One-Level Interactive response group
Distribution of routing methods on groups	Parallel routing: 40% Longest idle: 40% Serial: 10% Round robin: 10%	Parallel routing: 40% Longest idle: 40% Serial: 10% Round robin: 10%
Percentage of workflows that use speech recognition in their interactive voice response (IVR) versus workflows that use only dual tone multi-frequency (DTMF) in their IVR	Speech recognition/Text-to-speech (SR/TTS) + DTMF: 50% DTMF: 50%	SR/TTS + DTMF:50% DTMF: 50%
Number of hunt groups (mix of 50% simple and 50% complex hunt groups)	600	300
Average number of agents per group	10 agents	10 agents
Average number of groups an agent is a member of	Two groups	Two groups
Number of groups per queue (average)	90%: One group 10%: Two groups	90%: One group 10%: Two groups
Number of simultaneous response group calls	480	60
Average call duration (IVR portion + music on hold)	30 seconds	30 seconds
Average call duration with the agent	3 minutes	3 minutes
Number of sign-in/sign-out cycles for formal agents in a day (based on an 8-hour day)	4	4

Capacity Planning Requirements and Recommendations

The following tables provide information to facilitate capacity planning for your organization.

Table 7. Maximum Supported Users for Each Topology

Topology	Servers required	Maximum users supported
Standard Edition server	One Standard Edition server	5,000
Enterprise pool, consolidated configuration	Eight Enterprise Edition Front-End Servers running all server roles One Back-end SQL Server	100,000 Note: If deploying only IM and presence, Office Communications Server 2007 R2 supports 200,000 client end points, where each end point is a client program, such as Communicator, based on eight Front End Servers and a 16-core computer running the Microsoft SQL Server database software. The back-end database must run on a 4-way processor, quad core, or 8-way, dual core, 2.0 GHz+ computer.
Archiving Server	One Archiving Server	300,000
Monitoring Server	One Monitoring Server	200,000
Group Chat Server	Three Group Chat Servers	60,000 (20,000 per server). Note: You must deploy QFE 1 for this increased server and user support.

Edge Server topologies assume 10% of the total user base will be connected from outside the intranet. The following table shows the maximum number of client connections supported by each of the following Edge Server roles and topologies.

Table 8. Maximum Supported Clients for Edge Server Topologies

Topology	Supported performance
Edge Server	Access Edge service: 5,000 client connections Web Conferencing Edge service: 1,000 client connections A/V Edge service: 500 concurrent audio/video (A/V) sessions

Topology

Supported performance

Edge Server

Access Edge service: 5,000 client connections

Web Conferencing Edge service: 1,000 client connections

A/V Edge service: 500 concurrent audio/video (A/V) sessions

Deployment of a Director is recommended for external access.

Table 9. Communicator Web Access Capacity

Performance metric	Communicator Web Access presence and IM, Communicator Mobile for Java, search, and desktop sharing
Number of users	5,000 users 120 concurrent desktop sharing users

Performance metric

Communicator Web Access presence and IM, Communicator Mobile for Java, search, and desktop sharing

Number of users

5,000 users

120 concurrent desktop sharing users

Note:
Computer configuration: 2.3 GHz CPU, 8.0 GB memory, 8 processors, Kernel SSL disabled, ASP NET 1.5 request queue limit of 1.5 * the number of concurrent users of the server, HTTPS connection, no collocation with other virtual server or Office Communications Server, 16 GB virtual memory, Communicator Web Access logging (retail tracing) set to off

Note:
Computer configuration: 3.0 GHz CPU, 1.0 GB memory, 100 Mbps network, 80 GB hard drive, Internet Explorer 7.0 browser, Microsoft Windows XP SP2 operating system, 1280x1024 display

Table 10. Storage Disk Capacity Planning

Storage drive	Average disk bytes per read and average disk bytes per write (for 100,000 users)	Disk reads and writes (per second, for 100,000 users)
Enterprise pool backend data drive	Read: 0 Write: 2,180	Read: 0 Write: 158.3
Enterprise pool RTC log	Read: 0 Write: 832	Read: 0 Write: 216.2
Enterprise pool RTCdyn log	Read: 996 Write: 2,289	Read: 0.002 Write: 561.3
Archiving log file drive	Read: 0 Write: 3,783	Read: 0 Write: 110.1
Archiving data file drive	Read: 761 Write: 3,532	Read: 0.091 Write: 38.7
Monitoring (QoE and CDR) data log drive	Read: 8,192 Write: 6,213	Read: 85.5 Write: 193.1

Storage drive

Average disk bytes per read and average disk bytes per write (for 100,000 users)

Disk reads and writes (per second, for 100,000 users)

Enterprise pool backend data drive

Write: 2,180

Write: 158.3

Enterprise pool RTC log

Write: 832

Write: 216.2

Enterprise pool RTCdyn log

Write: 2,289

Write: 561.3

Archiving log file drive

Write: 3,783

Write: 110.1

Archiving data file drive

Write: 3,532

Write: 38.7

Monitoring (QoE and CDR) data log drive

Write: 6,213

Write: 193.1

Table 11. Archiving and Monitoring Database Storage Capacity Planning

Component	Average growth of database per hour	Usage assumptions
Archiving database	636 MB per hour per 100,000 endpoints	Based on 320 messages per second, 400 bytes per message
Monitoring database	CDR: 162 MB per hour for 100,000 endpoints QoE: 482 MB per hour for 100,000 endpoints	Assumes that clients do not create QoE data for video calls

Component

Average growth of database per hour

Usage assumptions

Archiving database

636 MB per hour per 100,000 endpoints

Based on 320 messages per second, 400 bytes per message

Monitoring database

CDR: 162 MB per hour for 100,000 endpoints

QoE: 482 MB per hour for 100,000 endpoints

Assumes that clients do not create QoE data for video calls

Table 12. Group Chat Capacity Planning

Chat room usage	User connection rate	Message rate
Each user participates in 30 chat rooms Each chat room has 30 participants	Two user connections initiated per second, per server	40 messages per second (all chat rooms)

Chat room usage

User connection rate

Message rate

Each user participates in 30 chat rooms

Each chat room has 30 participants

Two user connections initiated per second, per server

40 messages per second (all chat rooms)

Note:
Chat rooms can support more than 30 participants, and the Group Chat client is capable of supporting more than 30 chat rooms. However, large numbers of participants in a chat room may impact server performance. The maximum tested configuration for chat rooms is 1,000 participants. Use of chat rooms with large numbers of participants should be limited to no more than 10% of all chat rooms created.

Note:
Updated Group Chat capacity planning documentation, as well as a capacity planning spreadsheet, is available as a free download from the Microsoft Download Center: Capacity Planning for Microsoft Office Communications Server 2007 R2, Group Chat Server with QFE1 documentation: http://go.microsoft.com/fwlink/?LinkId=178622 Spreadsheet for Capacity Planning for Microsoft Office Communications Server 2007 R2, Group Chat Server with QFE1: http://go.microsoft.com/fwlink/?LinkId=178624

Note:

Updated Group Chat capacity planning documentation, as well as a capacity planning spreadsheet, is available as a free download from the Microsoft Download Center:

Capacity Planning for Microsoft Office Communications Server 2007 R2, Group Chat Server with QFE1 documentation: http://go.microsoft.com/fwlink/?LinkId=178622
Spreadsheet for Capacity Planning for Microsoft Office Communications Server 2007 R2, Group Chat Server with QFE1: http://go.microsoft.com/fwlink/?LinkId=178624

Table 13. Application Sharing Capacity Planning for Persistent Shared Object Model (PSOM) Applications

Application sharing usage	Sent and received (KBps)	Processor time	Average bandwidth usage per user (Kbps)
15 conferences, 90 users	Received: 1,370 (2,728 peak) Sent: 6,370 (12,315 peak)	Average: 8.5 Peak: 24.4	Sent per sharer: 713.57 Received per viewer: 552.92

Application sharing usage

Sent and received (KBps)

Processor time

Average bandwidth usage per user (Kbps)

15 conferences, 90 users

Received: 1,370 (2,728 peak)

Sent: 6,370 (12,315 peak)

Average: 8.5

Peak: 24.4

Sent per sharer: 713.57

Received per viewer: 552.92

Table 14. Mediation Server Capacity Planning

Computer	Maximum number of calls	T1	E1
90% internal users , 10% external/remote users
Dual processor, dual core, 3.0 GHz CPU, with 4 GB memory and 2 x 1 Gbps network adapter card	360	15	11
Dual processor, quad core, 2.3 GHz CPU, with 4 GB memory and 2 x 1 Gbps network adapter card	480	20	15
100% external/remote users
Dual processor, dual core, 3.0 GHz CPU, with 4 GB memory and 2 x 1 GB network adapter card	240	10	7
Dual processor, quad core, 2.3 GHz CPU, with 4 GB memory and 2 x 1 GB network adapter card	320	13	10

Note:
In the preceding table, CPU utilization is assumed to be 75% of capacity. Scaling numbers for Mediation Server depend on the location of the users, primarily how far the user is from the Mediation Server. For users outside the internal network, the media stack uses a lower bit rate, which can significantly impact performance.

Capacity planning for Address Book Server requires that you plan for the size of the Address Book Server database and Address Book Web query service database, the size of the download files, and the number of Office Communicator Mobile for Windows clients that will access the Address Book Web query service.

The size of the disk used for the Address Book Server database and the file server where Address Book Server creates download files depends largely on the number of contacts that must be stored. (The file server can be used to store other data as well. For details, see the “Folders” section in Storage Requirements.) One way that you can estimate the number of contacts that Address Book Server will store in the database and in the download files is to assume that each user has two Contact objects. As a result, you can estimate storage requirements for Address Book Server by multiplying the number of users in your organization by two.

General Address Book download file size assumptions:
- 100,000 contacts, 2.5 GB storage for download files (based on two contacts per employee)
- 100,000 employees, 5 GB storage for download files
General Address Book Web Query database size assumptions:
- 100,000 contacts, 1.5 GB storage
- 1 GB for database log

Table 15. Address Book Web Query Service Performance for an Enterprise Pool

Number of users	Maximum number of mobile devices	Number of entries in Address Book database	Queries per second	Usage notes
Total: 100,000 Voice-enabled: 30,000	18,000 (60% of Voice-enabled users)	300,000	Average: 17.7 Peak hours: 26.55	Eight Front End Servers 30% of users are enabled for unified communications. 100 queries per second has a minimal impact on performance.

Number of users

Maximum number of mobile devices

Number of entries in Address Book database

Queries per second

Usage notes

Total: 100,000

Voice-enabled: 30,000

18,000 (60% of Voice-enabled users)

300,000

Average: 17.7

Peak hours: 26.55

Eight Front End Servers

30% of users are enabled for unified communications.

100 queries per second has a minimal impact on performance.

Table 16. Audio/Video Capacity Planning

Media	Codec	Average bandwidth (Kbps)	Estimated activity (%)	Maximum bandwidth (Kbps)
Wideband Audio	RTAudio	34.8	61	57
Wideband Audio	Siren	22.2	43	51.6
Narrowband Audio	RTAudio	25.9	65	39.8
Video	RTVideo	258.3	82	350
Panoramic Video	RTVideo	220.5	70	350

Bandwidth numbers quoted for media streams include all overhead for framing, encryption, and IP routing information in addition to actual encoded media.
Average codec bandwidth values are based on measurements and derived from the maximum theoretical bandwidth based on typical activity level values. Audio activity levels take into account voice activity in the stream. Video activity levels take into account the amount of motion within the video images.
Activity levels for RT Audio Narrowband is slightly higher to allow for less optimal Voice Activity Detection in PSTN Gateways for Office Communications Server VoIP-to-PSTN calls. This number should be increased by another 15% if no Voice Activity Detection is enabled on the deployed PSTN Gateway.
Activity level of Panoramic Video is lower than for regular video streams because there is a higher relative proportion of background area within panoramic images.

Media Bandwidth Requirements and Recommendations

For basic media gateways, the bandwidth requirement between gateway and Mediation Server is 80 Kbps for each concurrent call. Multiplying this number by the number of ports for each gateway is a fair estimate of the required bandwidth on the gateway side of the Mediation Server. On the Office Communications Server side, the bandwidth requirement is considerably lower.

When configuring Mediation Server, you should accept the default media port gateway range of 60,000 to 64,000. Reducing the port range greatly reduces server capacity and should be undertaken only for specific reasons by an administrator who is knowledgeable about media port requirements and scenarios. For this reason, altering the default port range is not recommended.

High-bandwidth traffic such as voice and video tends to stress networks that are not appropriately provisioned. Limiting media traffic to a known range of ports makes troubleshooting such problems easier.

Mobile Data Bandwidth Requirements

Approximately 1 MB of bandwidth is required for mobile access for an 8-hour work day. This is based on the following usage:

One distribution group, with 15 users
80 members in contacts list, with four presence updates per user per hour
One tagged contact with four presence updates in one hour
12 phone calls per day, with 1 phone call per hour (1 incoming and 1 outgoing every two hours)
Two minutes per call
User is logged into one additional end point (such as Office Communicator or a desk phone)
One IM session every two hours
Outgoing and ingoing IMs are equal (1:1)