Posted in Skype for Business

Setting Up AudioCodes SBC IP Address via SSH

Connect to the appliance using putty.exe and run commands as example below.

configure voip

interface network-if display

interface network-if 0


prefix-length 27



Posted in Skype for Business

Functionality Comparison of Skype for Business – Cloud, On-Prem & Hybrid

Matrix Comparison

Functionality Skype for Business Online
Cloud PBX
(in Office 365, no on-premises Servers / Appliances)
Skype for Business Online
Cloud PBX
With Cloud Connector Edition (CCE)
Skype for Business Online
Cloud PBX
With Hybrid On-premises Servers
Skype for Business
Feature Description /
Additional information
Voicemail Yes, via Azure Voicemail (Exchange Online) or Exchange Unified Messaging (On Premises) Yes, via Azure Voicemail (Exchange Online) or Exchange Unified Messaging (On Premises) Yes, via Azure Voicemail (Cloud PBX / Exchange Online Users) or Exchange Unified Messaging (On Premises) Yes, via Exchange Unified Messaging (On Premises or Online) Voicemail support for Skype for Business is provided by Exchange Unified Messaging. Exchange Online users may also use Azure Voicemail, which delivers inbound voicemails to Exchange Online Mailboxes.
Broadcast meeting
(up to 10k users)
Yes Yes Yes, for online users only No produce and broadcast a meeting on the internet with up to 10,000 attendees, who can attend from a browser on virtually any device. With Skype Meeting Broadcast, you can host large virtual meeting such as internal “Town Hall” style meetings and public webinars. You can record meetings, and you can customize them to gauge audience involvement and satisfaction.
Call answer/initiate
(by name or phone number)
Yes Yes Yes Yes Standard Phone usage – Making and Receiving calls – Either from a Skype Certified Phone, a headset with the Soft client, or a mobile device.
Call delegation and call on-behalf (for example, manager and admin) Yes Yes Yes Yes Make or answer calls on behalf of a manager you support. Notifications make it clear to all participants when calls are being answered or made for someone else.
Call forwarding and simultaneous ringing Yes Yes Yes Yes These features allow you to set up forwarding rules so your calls can go with you anywhere, and you can forward calls to colleagues or to voicemail.
Call history Yes Yes Yes Yes Keep track of all your conversations in one place, whether those conversations are from IMs, phone calls, or impromptu and scheduled meetings. Conversations are recorded in your call history.
Call hold/retrieve Yes Yes Yes Yes Use when multiple calls occur at the same time. When you answer the next inbound call or place an outbound call, your current call goes on hold automatically.
Call Mute / Unmute Yes Yes Yes Yes Put active calls or conferences on Mute and unmute, either via Skype client mute Button, or dial controls when dialed in to conferences
Call transfer (blind, consult, and mobile) Yes Yes Yes Yes Transfers calls to another person. Or, if you need to leave your office, but want to continue your conversation, you can transfer the calls from your PC or IP phone, to your cell phone or tablet.
Caller ID Yes Yes Yes Yes External Calls that are not contacts or Federated contacts will show the caller ID info (phone number). Calls from inside your company display a detailed caller ID that pulls information from your corporate directory, showing you a picture and job title instead of just a phone number.
Camp On / tag for status change Yes Yes Yes Yes This feature allows you to tag people who are currently unavailable and get notified when their presence changes and they’re ready to take phone calls.
Desk Phone Support Yes Yes Yes Yes All version of Skype for Business support Skype Certified Desk phones and Headsets
Device switching Yes Yes Yes Yes Enables you to play your call or meeting on another device.
Dial-in Conferencing (up to 250 users) Yes Yes Yes Yes Dial in conferences can be supported on both Cloud and on-premises solutions. It should be noted that for Cloud deployments, on-premises PSTN cannot be used to join conferences (Online SIP trunking only)
Distinctive Ringing Yes Yes Yes Yes Play different ringtones for the different types of calls you get every day, so you quickly know who is calling you.
Do-not-disturb routing Yes Yes Yes Yes Controls your inbound communications with presence, enabling you to block all incoming communication except from those you specifically indicate.
Encryption Yes Yes Yes Yes Communications on all Skype options can be encrypted
Enterprise Calendar Call Routing Yes Yes Yes Yes Enterprise calendar call routing allows you to use your Exchange calendar business hours to enable or disable call forwarding and simultaneous ringing in Skype for Business.
High Availability Yes Yes Yes Yes High availability is built in to Cloud offerings, and on-premise solution support highly available and disaster-recoverable solutions.
Integrated dial-pad Yes Yes Yes Yes Dial by name or by number anywhere in the search bar and in the dial pad, speeding up the process of making outbound calls.
Integration with On-premises Exchange Unified Messaging Yes Yes Yes Yes Microsoft has recently added support for On-Premises Exchange Unified Messaging with Cloud PBX users. The details for this solution can be found here:
Make Skype for Business calls using your desk phone for audio Yes Yes Yes Yes When your PBX desk phone is configured to work with Skype for Business, you can call people in your organization through Skype for Business, and the audio for the call will flow through your phone.
Mobile Device Support Yes Yes Yes Yes All version of Skype for Business support Skype Clients on Windows, IOS or Android Mobile devices.
Music on hold Yes Yes Yes Yes Plays music when you place a call on hold, so your callers know you’re still there and the call hasn’t accidentally dropped.
Soft Client support (headset) Yes Yes Yes Yes All version of Skype for Business support Skype Clients on Windows and Mac.
Team calling (up to 25 users in a team) Yes Yes Yes Yes Sends your calls to your team either immediately or after a set time period.
Video call monitor Yes Yes Yes Yes You can see the speaker’s name and video stream in a small floating window, so you’re always ready to respond to any questions.
Web Conferencing (up to 250 attendees) Yes Yes Yes Yes Web conferences allow for attendees to join via the Skype for Business Client, a Lync client, or a Web-Based client for non-skype users.
Quality of Service (QoS) Requires Express Route Requires Express Route Yes for On-prem, requires express route for Cloud Yes QoS is supported in on-premises and Express Route deployments only.
Toll-free number support Yes Yes Yes Yes Toll-free numbers may be ported from your existing toll-free carrier.
Toll-Free numbers are also supported within PSTN conferencing on Office 365.
Requires on-premises servers or appliances No* Yes Yes Yes Pure Cloud PBX deployments require no on-premises servers or appliances. Cloud PBX with Cloud Connector can be a single server or appliance footprint.
* May require on-premise SSO, AD, etc.
Analog Device Support No Yes, with a gateway Yes Yes On-premises and Hybrid solutions allow for support of analog stations. Fax machines and modems are recommended to utilize POTS lines or PBX, and not flow through Skype.
Integration to On-premises PSTN No Yes Yes Yes With On-premises, Hybrid and CCE solutions, Skype can integrate to on-premise telephony (SIP trunks, PSTN, PBX, etc.)
Integration to PBX No Yes Yes Yes With On-premises, Hybrid and CCE solutions, Skype can integrate to on-premise telephony (SIP trunks, PSTN, PBX, etc.)
Abbreviated Dialing No Requires On-premise Gateway Yes Yes Abbreviated dialing refers to the ability to short-dial (4-digit for example) users within the organization. It should be noted that when utilizing Skype for Business, abbreviated dialing becomes essentially eliminated – as click to call works for all peer-to-peer calls in skype clients.
For more info about Configuring abbreviated dialing in a cloud connector edition scenario, see the link below:
Outbound DID Manipulation No Requires On-premise Gateway Yes Yes One-premise, Hybrid and CCE deployments allow the administrator to manipulate outbound dialing strings from users for normalization or call routing. This is largely irrelevant in Cloud PBX deployments, as there is no Least cost routing or digit manipulation required in most instances,
Call Parking Lot No No Yes Yes On-premises and Hybrid deployments allow you place a call in a parking lot, and allow another user to dial the park number to retrieve the call. This is not yet available in Cloud PBX.
Contact Center Integration Only Client-side integration Only Client-side integration Yes Yes Cloud PBX does not currently allow for 3rd-party integration to the backend servers, and thus Contact centers will require on-premises of Hybrid deployment for direct integration.
Client-side integration IS available from Clarity Connect, in a cloud-based federation service.
E911 No* No* Yes Yes * US-originated 911 calls are sent to a third-party handler that will determine the caller’s location, and route the call to the correct PSAP.

Calls originating from the UK will route directly to the PSAP that correlates with the user’s location information in Skype Online.

Least Cost Routing N/A N/A Yes Yes On-premises deployments are able to route calls to specific Skype pools or devices based on the dialed number. This feature is irrelevant in Cloud PBX.
Private Line No No On-prem users only Yes On-premise users are able to have a second, unpublished private line. This line could have a separate ring tone, and could be an executives personal line.
Transfer to Voicemail No No On-prem users only Yes Users located on-premises will be able to transfer calls directly to another on-premise user’s voicemail. Cloud users will be required to transfer the call back to the user, which would ring their phone before routing to voicemail.
Common-Area Phones Requires a license Requires a license Requires a license for cloud based Yes Phones that are not assigned to a user are allowed in Skype On-premises solutions and Hybrid, but Cloud offerings will require that those use a user account (BreakRoom1 for example), and will require a license.
Branch Survivability No No For on-prem users only Yes In on-premises solutions, you are able to place a gateway with Survivable Branch appliance functionality at Branch locations. This will allow users to continue using PSTN even in a primary site or WAN outage.
Busy options No No For on-prem users only Yes Users in on-premises solutions can determine what happens to communications based upon their free-busy status.
Call Admission Control N/A N/A For on-prem users only Yes On-premises solutions have the ability to route incoming communications to other Skype pools based upon over-utilization. This feature is irrelevant in Office 365.
Response Groups Call Queues Call Queues Yes for on-prem, Call Queues for Cloud Yes Response groups are hunt groups within Skype for business, and currently only supported in on-premises or Hybrid solutions (And Response group users must reside in the on-prem Skype deployment).
Call Queues enables incoming calls to route to the next available attendant in the order that they were queued.
Shared Line Appearance No No For on-prem users only Yes Shared Line Appearance is a feature in Skype for Business on-premises deployments for handling multiple calls on a specific number called a shared number. SLA can configure any enterprise voice enabled Skype for Business user as a shared number with multiple lines to respond to multiple calls.
Public meeting support (Static ID) No No For On-prem meetings only Yes When a meeting is generated in Skype online, it is given a new meeting ID every time, and expires in 15 Days. For on-premise Skype Meetings, users have the option to select whether they want a unique meeting ID, or their static meeting ID (which is always available to dial in to).
International Support Limited Limited Yes Yes Cloud PBX support native PSTN calling in the US, UK, France and Puerto Rico only. Users outside of these countries may use PSTN calling (Excluding India), but they would have US phone numbers, and be routed via the US datacenter.
International plans include 600 minutes per user per month and minutes can be pooled across users.
Call Quality Logs Yes Yes Yes Yes On-premises solutions allow for a deployment of the monitoring server service, which writes to SQL. The monitoring service in Skype for Business Server 2015 provides a way for administrators to collect usage and quality data for the communication sessions that take place in their organization, which allows them to identify trends and problems.

Cloud solutions offer the Call Quality Dashboard, and some powershell commands to assist in trending and troubleshooting.

Room system integration Yes* Yes* Yes Yes * Rooms systems that are not on the Skype-supported list may require a 3rd party integration solution such as Pexip. The Skype supported Room Systems can be found here:
Skype on-premises solutions have more flexibility in regards to integration with existing room systems.
Call recording Client only Client only client only for cloud users Yes Skype clients have ability to locally record calls on-demand, but for backend call recording solutions, on-premises deployment is required.
Auto-attendants Yes Yes Yes Yes Organizational Auto Attendant is a new feature in Cloud PBX that allows admins to configure an automated system to answer inbound calls to their company, ask the caller using speech recognition for their intended destination, and route the calls accordingly to users and departments inside the company.
On-premises Skype for Business requires Exchange Unified Messaging (Cloud or on-premises) for support for Auto-Attendants (and voicemail).



Posted in AudioCodes, Skype for Business



You have configured the AudioCodes Gateway (M800, M1K, M2k) with the best of your knowledge. Numbers manipulations are all correct in your view. You are sending the call to PSTN however call is simply dropping and you encountered below errors on logs.


Other errors on the logs:

  • pstn recv <– CALL_RELEASED Trunk:0 Conn:0 RetCause:104 NetCause:44
  • Abnormal Disconnect cause:44#GWAPP_REQUESTED_CIRCUIT_NOT_AVAILABLE Trunk:0 Conn:0
  • LOCAL_CALL_RELEASED_EV(Trunk:0 Conn:0 Bchannel:28 TpEv=68)

So what’s wrong??!!

First, ask your customer if how many E1 or T1 channels they purchased. Usually as Voice engineers, we are used to use 1-24 for T1 and 1-31 for E1 in Trunk Configuration however if for example your customer only bought 10 channels, you must specify it in Trunks configuration correctly like 1-10 range only. Otherwise, you will meet above errors.

Hope it helps you!!



Posted in Exchange UM, Lync Server 2013, Skype for Business

Exchange Web Services (EWS)

Exchange Web Services (EWS) is a service used by Lync/SfB to integrate with Exchange. Successful integration obtains:

  • Calendar
  • Free/Busy information
  • Save Conversation History
  • High Resolution Photos
  • Voice Mail Access

Lync/SfB Client process to connect to Exchange Web Services (EWS)

1. Client will attempt to read any existing Autodiscover data with a valid Time-to-Live (TTL), which may have been previously retrieved by Outlook.
2. Client or device will extract the SMTP domain from the user’s presence document.
3. Client or device will then use the user’s SMTP domain to construct DNS queries for the following URLs:
a. https:///autodiscover/autodiscover.xml -if fails, goes to b.
b. https://autodiscover./autodiscover/autodiscover.xml -if fails, goes to c.
c. http://autodiscover./autodiscover/autodiscover.xml -if fails, goes to d.
d. Autodiscover uses DNS SRV lookup for, and then “” is returned.
4. Client asks permission from the user to continue with Autodiscover to post to
5. Autodiscover’s POST request is successfully posted to

Posted in Exchange UM, Lync Server 2013, Skype for Business

Script: Creating Self-signed Exchange UM Certificate

Here’s the thing, I want to post this since I always forgot this syntax every time I’m in the field integrating Lync/SfB and Exchange UM. I tested it over Exchange 2013 UM and setup is on-premise.

New-ExchangeCertificate -FriendlyName ‘LyncUM’ -PrivateKeyExportable $true -KeySize ‘2048’ -SubjectName ‘C=SG, O=LNC,’ -DomainName ‘’ -Services ‘UM,UMCallRouter’ -Server ‘’

Posted in Lync Server 2010, Lync Server 2013, Skype for Business

Outlook Conversation History vs. Lync/SfB IM Archiving

Note: The credit for this explanation does not belongs to me. I got this few years ago and save on my notepad but I forget to give credit to the author. If you read this, please comment.

The conversation history you are seeing in outlook is nothing to do with your archiving. Implementing Lync/SfB along side Exchange is giving you that functionality. This is a users personal conversation history, that they can refer to and manage as they see fit – and yes it contributes to the size of their mailbox but it’s insignificant size.

An archiving server on the other hand, stores IM and conferencing data to SQL. Archiving is normally deployed if a company needs to meet regulatory requirements, or would like to archive IM data for a period of time for their own personal ‘safety net’ reasons. If a user deletes something from their personal conversation history (mailbox) it is not removed from the server side archiving.

Retention policies and configuration is used on the server side archiving to determine how long you would like to keep data in the store, and how often to purge said data etc.

Question: Are we duplicating data?

Answer: Yes, but for two very different reasons.

One is manageable by the end user, and exists for their use, reference and history purposes. The other managed by administrators and used as the ‘go to’ point regarding incidents etc. A user could send an abusive IM then delete it from his own history, the purpose of an archiving server nullifies his attempts at covering things up.

Mailbox impact is trivial regarding conversation history.

Posted in Lync Server 2013, Skype for Business

Script: Creating Lync or SfB Databases with Specific Path

Install-CsDatabase -CentralManagementDatabase -SqlServerFqdn -SqlInstanceName rtc -DatabasePaths “G:\CSDB”

Install-CsDatabase -ConfiguredDatabases -SqlServerFqdn -DatabasePaths “E:\CSLog”,”F:\CSLog”,”G:\CSDB”

Install-CsDatabase -DatabaseType Monitoring -SqlServerFqdn -SqlInstanceName SGLYNCMON -DatabasePaths I:\MonitoringLogs,H:\MonitoringData

Install-CsDatabase -DatabaseType Archiving -SqlServerFqdn -SqlInstanceName SGLYNCARC -DatabasePaths I:\ArchivingLogs,H:\ArchivingData



Uninstall-CsDatabase -DatabaseType Monitoring -SqlServerFqdn -SqlInstanceName SGLYNCMON
Uninstall-CsDatabase -DatabaseType Archiving -SqlServerFqdn -SqlInstanceName SGLYNCARC