Upload
aruba-networks-an-hp-company
View
873
Download
4
Tags:
Embed Size (px)
Citation preview
CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved
2 #AirheadsConf
Agenda
• Why UC and Wi-Fi?• Challenges with Real Time Media & Wi-Fi• Common Usage Scenarios• Lync over Wi-Fi Multi-Tier Strategy • Wi-Fi Deployment Guidance for Real Time Media• Configuring QoS for Lync• Lync SDN Program• Q&A
CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved
3 #AirheadsConf
Why care about UC and Wi-Fi?
• UC is about a communication and collaborative experience anywhere and on any device
• Wi-Fi by default, wired when necessary (in many cases Wi-Fi only)
• Network managers tasked to plan for (data/voice/video) Wi-Fi convergence
• Customers are pushing towards greater real time media over mobile scenarios
• Wi-Fi has become a mainstream wireless technology
4CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved
#AirheadsConf
Challenges with Real Time Media & Wi-Fi
5CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved
#AirheadsConf
Real Time Media
• Streaming vs. Real Time Media– Streaming applications like YouTube, Netflix, etc can utilize large
receive side buffers in order smooth out network delays
– Real Time Media is interactive and requires a high performance network that can sustain continuous up/down stream traffic, with low latency, jitter and packet loss
• Impact to Human Interaction– Human communication starts to get negatively impacted with
latency of more than 250 msec (one way, mouth-to-ear latency)
– Bursty jitter or packet loss over a certain threshold cannot be recovered, and leads to glitches in the audio and video stream
– Audio glitches are very disruptive and lead to a poor user experience
6CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved
#AirheadsConf
Real Time Media Network Requirements
• Bandwidth requirements (1)
– Audio 50 Kbps to 220 Kbps per stream (incl. IP header and FEC overhead)
– Video 250 Kbps to 4 Mbps per stream
• Jitter – Desired jitter less than 20 msec
• End-to End Network Latency– Desired less than 100 msec (one way)
– Acceptable less than 200 msec (one way)
– Depends on geography
• Packet Loss– Desired 0%, acceptable <2% and not more than 3 consecutive lost packets
• UDP vs. TCP – Both UDP and TCP are supported for Lync 2013 Real Time Media
– UDP is preferred for Real Time Media as TCP recovery (retransmits) is usually too long to be useful
7CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved
#AirheadsConf
Real Time Media Issues When Running Over Wi-Fi
• Handover Performance– Real Time Media has very different requirements when roaming between
APs then when stationary
– Delayed handovers from “sticky clients” can result in multi-second media breaks for voice/video
– Clients often “stick” to an Access Point (AP) even when the signal strength has deteriorated so far as to be unusable
– And at the opposite extreme, some clients may “ping-pong” rapidly between multiple APs or SSIDs
•Off-Channel Scanning– Background scanning mechanisms are off-channel too long and inconsistent
which may affect media traffic
8CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved
#AirheadsConf
Real Time Media Issues When Running Over Wi-Fi (cont.)
•Rate Adaption and TX Retries– Existing rate adaption algorithms not well suited for Real Time Media
– May take up too much airtime in retries when used for Real Time Media traffic
•Media Admission Control– Need a mechanism to prevent oversubscription of high priority traffic
– Optimizing available resources via load balancing, steering clients away from congested APs, facilitating good roaming decisions, and avoiding low data rates are preferable to denying new sessions (only used as a last resort)
•SNR and signal strength requirements are different between Real Time Media and data
– Data - SNR better than 25 db and RSSI better than -90 dBm
– Real Time Media - SNR better than 40 dB and RSSI better than -65 dBm
9CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved
#AirheadsConf
Wi-Fi Deployment Guidance for Real
Time Media
10CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved
#AirheadsConf
Running Lync 2013 over Wi-Fi
• Data over Wi-Fi
• Devices - Desktops, laptop, slates, mobile smart phones
• Modalities - IM, presence, web conferencing, calendaring
• Real Time Media over Wi-Fi: Fixed
• Additional modalities (includes Lync Data over Wi-Fi) - Voice mail, video conferencing, telephony, audio conferencing
• Nomadic but stationary use of Lync services
• Real Time Media over Wi-Fi: Mobile
• Modalities same as with Lync Real Time Media over Wi-Fi Fixed
• Originate, consume and terminate Lync services while on the move
11CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved
#AirheadsConf
Wi-Fi Deployment Guidance
Enterprise Infrastructure Recommendations
• Deploy 802.11ac APs AP-225 or AP-205• Enterprise Wi-Fi controller with thin enterprise grade APs or
standalone APs• Implement WPA2 in Enterprise Mode• Fast BSS transition support (OKC and/or 802.11r)• Configure for load balancing across AP’s• QoS/WMM Planning
• Ability to classify and prioritize Lync traffic (SIP-TLS) in the presence of lower priority data traffic
• Implement QoS throughout wired and wireless infrastructure to prioritize voice and video
• Implement QoS/WMM with EF queue for WMM Voice
• Enable WMM on APs for QoS. Enable QoS on Lync servers and clients
• Enable power saving mechanisms
12CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved
#AirheadsConf
Wi-Fi Deployment Guidance
Enterprise Infrastructure Recommendations• RF Planning
• Deploy APs featuring dual (concurrent) 2.4 GHz and 5 GHz operation with 3x3 configuration and 1 Gbps backhaul
• 2.4 GHz band - drop 802.11b support, limit 802.11n support to 20 MHz channels
• 5 GHz band - if available, enable “RF band steering” to move dual-band client devices to 5GHz RF, use 40 MHz channel
• Support for RF auto radio management of channel and signal strength
• Capacity Planning• Deploy applicable AP density for required coverage and capacity but keep signal
levels better than -65dBm and SNR better than 40dBm (association and roaming probe responses should have SNR better than 25dBm)
• Deploy sufficient number of APs for seamless coverage
• Design for capacity based on # of clients in coverage area
• Plan for overlapping AP coverage (redundancy) as required
• In large conference rooms deploy multiple APs
13CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved
#AirheadsConf
Wi-Fi Deployment Guidance
Enterprise Physical Infrastructure Recommendations• Physical cell deployment
– Open space design is different from walled office designs
• RF Coverage – Ubiquitous Wi-Fi coverage is required!
– Signal strength in coverage footprint (-65dBm or better)
– Surveys– Baseline
• Spot Testing
• Walkthrough testing
• Roaming with Lync Client session calls
– Periodic surveys to ensure baseline performance remains consistent
14CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved
#AirheadsConf
Wi-Fi Deployment Guidance
Enterprise Client Recommandations• Enterprise class devices (e.g. tables, laptops)
• BYOD is a reality so be prepared
• Mobile devices supporting dual band• Real Time Media optimized/certified NIC and drivers
• Manage NIC driver versions
• Note: When on battery power drivers tend to reduce Wi-Fi device power
• High-quality dual band NIC with at least 2x2:2 configuration
• Support for radio resource management (802.11k)
15CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved
#AirheadsConf
Configuring QoS for your Lync deployment
16CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved
#AirheadsConf
DiffServ QoS Model
Precedence Level
DiffServ Marking
ToS Name Description
7 DSCP 56 (CS7)
Network Control
Reserved for IP routing protocols
6 DSCP 48 (CS6)
Internetwork Control
Reserved for IP routing protocols
5 DSCP 40 (CS5)
CRITIC/ECP Express Forwarding (EF)
4 DSCP 32 (CS4)
Flash Override Class 4
3 DSCP 24 (CS3)
Flash Class 3
2 DSCP 16 (CS2)
Immediate Class 2
1 DSCP 8 (CS1)
Priority Class 1
0 DSCP 0 (Default)
Routine Best Effort
Drop Precedence
Class 1 Class 2 Class 3 Class 4
Low DSCP 10 (AF11) DSCP 18 (AF21)
DSCP 26 (AF31)
DSCP 34 (AF41)
Medium DSCP 12 (AF12) DSCP 20 (AF22)
DSCP 28 (AF32)
DSCP 36 (AF42)
High DSCP 14 (AF13) DSCP 22 (AF23)
DSCP 30 (AF33)
DSCP 38 (AF43)
Assured Forwarding
Scheduler
Drop
High
Drop
Med
Drop
Low
Drop Zone
EF
AF
CS3
Best Effort
Committed Rate Queue
Committed Rate Queue
INPUT
OUTPUT
Strict Priority Queue
Ingress Rate < Egress Rate
Committed RateDefined
Committed RateDefined
Committed RateDefined
No RateDefined
Expedited ForwardingDiffServ Marking
Description
DSCP 46 (EF)
low delay, low loss and low jitter
17CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved
#AirheadsConf
Expedited Forwarding (EF) Behavior
Scheduler
Drop High
Drop Med
Drop Low
Drop Zone
EF
AF
CS3
Best Effort
Committed Rate Queue
Committed Rate Queue
INPUT
OUTPUT
Strict Priority Queue
Ingress Rate < Egress Rate
Committed RateDefined
Committed RateDefined
Committed RateDefined
No RateDefined
18CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved
#AirheadsConf
Expedited Forwarding (EF) Behavior
Scheduler
Drop High
Drop Med
Drop Low
Drop Zone
EF
AF
CS3
Best Effort
Committed Rate Queue
Committed Rate Queue
INPUT
OUTPUT
Strict Priority Queue
Ingress Rate < Egress Rate
Committed RateDefined
Committed RateDefined
Committed RateDefined
No RateDefined
QoS engineering has to be managed consistently end-to-end, or it can have a dramatic negative impact to all real-time voice and video traffic
19CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved
#AirheadsConf
Todays IP Phone QoS Model
Marked by switch asBest Effort (BE) for 802.1p and DSCP
Data VLAN
Marked by switch asExpedited Forwarding(EF) for 802.1p and DSCP
VoIP
DataTerminal
BE Queue
Access Switch
EF Queue
Data VLAN
Voice VLAN
Voice VLAN
Scheduler forEF and BE Traffic
Behavioral Aggregate Classifier For EF and BE Traffic
Scheduler forEF and BE Trafficwith Mappings form DSCP to 802.1p
DataTraffic
VoiceTraffic
Data Server
IP PBX
802.1PClassifier
PSTN
Non-Secured
Secured
IP Phone QoS is Secured
20CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved
#AirheadsConf
Todays UC&C QoS Model
Marked by Lync endpoint for DSCP• Voice - Expedited Forwarding (EF)• Video – Assured Forwarding (AF)• Data - Best Effort (BE)
DataTerminal
Access Switch
Scheduler forEF, AF & BE Traffic
Behavioral Aggregate Classifier For EF, AF & BETraffic
Scheduler forEF, AF & EF Traffic. with Mappings from DSCP to 802.1p
Voice, Video &Data Traffic(802.1p and
DSCP Marked)
802.1PClassifier
PSTN
Lync
Voice, Video &Data Traffic(802.1p and
DSCP Marked)
Scheduler forEF, AF & EF Traffic. with Mappings from DSCP to 802.1p if needed
AP
Wi-Fi
Marked by Lync endpoint for WMM and DSCP• Voice - Expedited Forwarding (EF)• Video – Assured Forwarding (AF)• Data - Best Effort (BE)
Remark QoS for Untrusted traffic to
Best Effort
One of the biggest issues for Lync is that Network Elements are misconfigured for QoS and/or network policies remark untrusted traffic to Best Effort
Result is poor Lync experience for voice and video
21CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved
#AirheadsConf
Automated QoS and TE
UC / Application Admin
Time in Weeks
Ongoing Monitoring &
Troubleshooting
Identify traffic
classes
Configure UDP ACLs
on Switches
Inventory WAN circuit
sizing
What Codecs
?
Remark DSCP for untrusted applications?
Lock down UDP port
ranges used for voice/video
Identify sites
Define Erlang traffic
models
Provision CAC
across sites
Validate SLAs
Ok, ready to start rolling out
Enable DSCP…on all
endpoints
…Network Admin
SDN will reduce cost of deploying QoS, Traffic Engineering and Security for UC
22CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved
#AirheadsConf
Lync QoS Recommended Guidance
23CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved
#AirheadsConf
Lync QoS Guidance
• Configure port ranges– Use same media ports across Lync server media roles for same modality type (e.g. audio)
– Use non-overlapping media ports across Lync server media roles for different modality types (e.g. audio vs video)
– Make client audio/video port ranges subset of servers
• E.g. server audio port range = 49,152 – 57,500
• Client audio port range = 50,020 – 50,039
• Configure QoS– Quality of Service Policy on Windows Vista/7/8 and Windows Server 2008 R2/2012
– QoS Packet Scheduler on Windows XP w/ controlled load (video, DSCP 34) and guaranteed service type (audio, DSCP 46)
• Set-CsMediaConfiguration -EnableQoS $True
– Lync Phone Edition is using DSCP 40 for audio (change with Set-CsUCPhoneConfiguration -VoiceDiffServTag 46)
– Lync for Mac 2011 is using CS5 (0x28) for audio and CS3 (0x18) for video
– Lync Mobile clients use hardcoded QoS Values
24CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved
#AirheadsConf
Lync QoS Guidance
Config upstream QOS Policy for Lync desktop client• For Lync client on Windows 7/8
– In Group Policy Editor go to Computer Configuration -> Windows Settings -> Policy-based QoS
– Gpudate.exe /force
– On multi-adapter and/or Workgroup Mode computer set “Do not use NLA”=”1″ under HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\Tcpip\QoS
Client Traffic Type
DSCP
Source IP
Destination IP
Protocols
Source port range
Destination port range
Audio 46 Any Any TCP/UDP
50020:50039
Any
Video 34 Any Any TCP/UDP
58000:58019
Any
App Sharing
24 Any Any TCP/UDP
42000:42019
Any
File Transfer
14 Any Any TCP/UDP
42020:42039
Any
25CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved
#AirheadsConf
Lync SDN Program
26CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved
#AirheadsConf
Today’s UC&C challenges
• Network issues cause 60-80% of poor end-user QoE
• Poor visibility into real-time traffic– Lync uses encryption by default, making DPI difficult and
unreliable
– Skype tries to hide itself from networks
• Traffic engineering / QoS is complex & easily broken– Requires brute force static policies that must match
application server settings
– Intermittent problems are tedious to diagnose, especially for Softphones and BYOD
27CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved
#AirheadsConf
Why SDN
• Addresses increasing complexity
• Realize operational efficiencies
• Improves end-user experience
Visibility
Control
Automation
Agility
28CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved
#AirheadsConf
What is Application Driven SDN
App App App App
SDN Controller Platform
NE
NE
NE
NE
Northbound Interface
Southbound InterfaceAbs
trac
tion
SDN Application• Logic and Network Service
Intelligence
Controller• Centralized Control
System• Global view
Network Elements• Physical or virtual
forwarding path
Applications Programing Networks
29CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved
#AirheadsConf
“Network Service Application” Driven SDN Model
NetworkElement
NetworkElement
NetworkElement
NetworkElement
NetworkElement
NetworkElement
NetworkElement
SDN Controller Topology Inventory Flow Programming Statistics
Network Service Application
Network Service Logic Policy
SDN Controller North-Bound Interfaces
Administrator Interface
30CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved
#AirheadsConf
“End User Application” Driven SDN Model
NetworkElement
NetworkElement
NetworkElement
NetworkElement
NetworkElement
NetworkElement
NetworkElement
SDN Controller Topology Inventory Flow Programming Statistics
Network Service Application
Network Service Logic Policy
SDN Controller North-Bound Interfaces
Administrator Interface
Abs
trac
tion
End User App(Ex: UC)
Network ServiceNorth-Bound Interface
31CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved
#AirheadsConf
UC SDN Architecture
32CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved
#AirheadsConf
UC SDN Dialog Event
33CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved
#AirheadsConf
UC SDN Quality Update Event
34CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved
#AirheadsConf
Basic Architecture and Flow (V2.0)
35CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved
#AirheadsConf
Redundant Architecture and Flow (V2.0)
ClientLyncClient
Lync FE + LDLLync FE + LDL
PrimaryLync SDN Manager
Secondary Lync SDN Manager
Fault-tolerance, Pools and Fan-Out:
NMS/Network ControllerNMS/Network ControllerNetwork
Controller
36CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved
#AirheadsConf
Redundant Architecture and Flow (V2.0)
ClientLyncClient
Lync FE + LDLLync FE + LDL NMS/Network
Controller
PrimaryLync SDN Manager
Secondary Lync SDN Manager
Fault-tolerance, Pools and Fan-Out:
NMS/Network ControllerNetwork
Controller
37CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved
#AirheadsConf
Initial Features Lync SDN API V2.0
• Lync SDN Manager• Basic filtering, aggregation, augmentation,
dispersion (stateful)• No LDL changes. Backward compatibility• Support for primary/secondary redundancy
38CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved
#AirheadsConf
Architecture V2.1- Coming Out Soon
LFE+ LDLLync FE + LDL Lync SDN
ManagerLync SDN Manager
Load-balancing, pools, state & configuration sharing:
FE + LDLLync FE + LDL
Shared State
Configuration
Configuration
Additional message type:IncallQuality
Database or shared memory cache
NMS/Network ControllerNMS/Network ControllerNetwork
Controller
39CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved
#AirheadsConf
Lync SDN API V2.1Features
• In-call Quality Updates • Full load-balanced and redundancy pool• State sharing using a database• Simplified configuration and setup of LDL• Internal re-organizing• Move computation from LDL to SDN Manager• Partner requests
40CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved
#AirheadsConf
Where We Are Today
• Lync SDN API v2.0 Publically Available
• API can be installed on Lync 2010 and Lync 2013
• LDL Must be installed on all FEs
– Continuing to advance the API with partner’s requirements
41CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved
#AirheadsConf
Lync UC SDN Scenarios
42CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved
#AirheadsConf
UC SDN Scenarios Being Defined
• Automated Diagnostics: – Pinpoint root-cause-analysis for degraded media calls
• Automating QoS– Dynamically mark authorized voice and video traffic with the appropriate QoS markings.
• Dynamic Traffic Engineering of Bandwidth Capacity for each Class of Service: – Dynamically adjust the amount of bandwidth associated with various Classes of Service (CoS) to match bandwidth requirements of the
corresponding applications.
• Call Admission control: – Prevent voice and video traffic from exceeding the available bandwidth capacity, and notify applications of changes in available bandwidth
so they can adjust selected codecs (e.g. based on policies).
• Dynamic Traffic Engineering of Media Paths: – Route media along a path that is best able to meet performance requirements (rather than along the “default” least-cost path).
• Security DDOS and IPS/IDS orchestration:– Positive identification of authentic media flows to prevent scrubbing
• Firewall orchestration: – Automating pinhole firewall provisioning of dynamic media flows
• Wi-Fi orchestration: – Automating real-time-media flows over Wi-Fi for correct behaviors of STAs and APs for many scenarios
43CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved
#AirheadsConf
Lync and Aruba SDN Collaboration
44CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved
#AirheadsConf
Aruba SDN Overview
• Aruba Controller as the consumer of Lync SDN messages– PEF engine and roll based access
– Voice subsystem to collect WiFi statistics
– QOS to mark and prioritize
• SDN acts as a trigger• Additional data from SDN adds correlated data• Flow is unidirectional today
45CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved
#AirheadsConf
Lync SDN – QoS Flow
1. User establishes Lync call to another device– Call setup is through Lync Front End
server, call is peer-to-peer
2. Lync server sends session information to Controller via SDN API to web services listener
3. Controller uses data for QoS and AppRF visibility– Voice Video Desktop Sharing DSCP
mappings are made in SSID profile
1
3
2
46CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved
#AirheadsConf
Lync SDN – Collecting call data
1. At the end of each call, participants send Quality of Experience (QoE) data to the QoE server, which is a component of Lync
2. The QoE server reports stats to the controller
3. Controller builds monitoring pages
1
3
2
59CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved
#AirheadsConf
MS Link Overview
60CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved
#AirheadsConf
Lync Components
Media for callbackSIPhttps (XML)
Push notification for Windows Phone
Media gateway
Media server Front End server
Reverse proxy
DMZ
WiFi
Internet
Lync push notification
services
Edgeserver
• AD• DNS• Exchange• Front End server• QOE server• Reverse Proxy• Edge Server
61CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved
#AirheadsConf
Client sign-in Lync 2013
• A record Lyncdiscover.<sipdomain>
Lync client
DNS Server
Front End
Reverse Proxy
Edge Server
Data center 1
Front End
Reverse Proxy
Edge Server
Data center 2
1. Query for Lyncdiscover. <sipdomain>
2. DNS points to Reverse Proxy
3. Client connects to Reverse Proxy
5. Client directly connects to local
4. Returns local Access Edge
62CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved
#AirheadsConf
Lync Signaling Ports
TCP Port
Lync Internal 5061
Lync External 443
Office 365 443
63CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved
#AirheadsConf
Understanding Lync Bandwidth Requirements
Lync bandwidth usage is variable but predictable
http://technet.microsoft.com/en-us/library/jj688118.aspxBandwidth Calculator Tool:http://www.microsoft.com/en-us/download/details.aspx?id=19011
Codec Bandwidth
Voice Wideband Audio 91Kbps (MAX) / 39.8Kbps (Avg)
Video 1280x720 h.264 2510Kbps (MAX) / 460Kbps (Avg)
5 person video call (MAX) (5 x 2510) + (91 * 2) = 12.43Mbps
5 person video call (Avg) (5 x 460) + (39.8 * 2) = 2.32Mbps
This represents high end codec use, additional info at: