Derdack

Targeted Alert Notifications – Anywhere Actions

Derdack
  • Use Cases
    • Overview
    • Enterprise IT Alerting
    • IT Managed Services
    • Mobile Alerting in Manufacuring
    • Critical Operations Alerting in Banking & Financial
    • Field Service Dispatching in Energy & Utilities
    • Use Cases in other Industries
  • Products
    • Overview
    • Enterprise Alert®
      • Overview
      • Alert Notifications
      • On-call Duty Scheduling
      • Collaboration
      • Anywhere Remediation
      • Incident Mgmt. App
      • Integrations
      • Technical Support
      • Online Knowledge Base
      • Derdack FAQ
    • SIGNL4® Cloud
    • References & More
  • How to Buy
    • Overview
    • Pricing and Quotes
    • Azure Marketplace
  • About Derdack
    • About
    • Careers
    • Strategic Partners
    • Derdack Podcast
    • Contact Derdack
  • News & Blog
  • Request Demo
    • de de
  • News & Blog

    • Home
    • News & Blog
    • Technical
    • All about Phone Calls in Enterprise Alert: VoIP Requirements and Capabilities

    All about Phone Calls in Enterprise Alert: VoIP Requirements and Capabilities

    • July 8, 2016
    • Technical
    All about Phone Calls in Enterprise Alert: VoIP Requirements and Capabilities

    Enterprise Alert provides so many great alert notification and remote incident managed scenarios. The ones that I personally like most are based on voice call notifications or conferences. To get these scenarios to work Enterprise Alert needs to be connected to a VoIP system in order to be able to call phones and be called by users. In this blog article, I’d therefore like to document the requirements and capabilities for Enterprise Alert when implementing voice calls.

    Basics

    Enterprise Alert does VoIP i.e. it does standard Voice over IP. What this means is described in the protocols section, but I thought it makes sense to clarify that we don’t connect to PBX systems with a phone card in the server. We have focused on VoIP as this IP-based technology simplifies virtualization and is more adequate in the cloud world.

    However, if you really want to go for analog or ISDN-based phone calls, you need to think about how Enterprise Alert can talk VoIP with the corresponding hardware card. In case of Dialogic Media Boards, there used to be a VoIP-based endpoint that they called Dialogic SIP Control. It came with the Dialogic driver suite and provided a great VoIP Server for Enterprise Alert. That meant that Enterprise Alert talked VoIP with the Dialogic SIP Control on the host where Enterprise Alert is running and the media board is located. I’m not sure if Dialogic still supports SIP Control or how it is licensed.

    VoIP Protocols

    Enterprise Alert supports the following VoIP protocols.

    Signaling

    1. SIP Protocol as defined in RFC 3261
    2. Session description according to SDP as defined in RFC 4566
    3. Transport protocol can either be TCP/IP or UDP as suggested in RFC 3261
    4. Enterprise Alert supports “Early Offer” only, meaning that each INVITE MUST contain the SDP PDU in the INVITE body for incoming calls to EA. Early Offer can be activated in almost all VoIP Servers.
    5. Enterprise Alert can connect to the VoIP system either as Trunk or as a Phone endpoint. Connecting Enterprise Alert as Phone Endpoint is not recommended, simply because Enterprise Alert itself is more a phone server that manages calls on behalf of others i.e. Enterprise Alert is not a user in the calls and serves more as a gateway that connects people to each other. When it is connected as a phone endpoint it sends SIP REGISTER requests in the interval that the server specifies, which adds unnecessary network overhead. When connected as trunk there are no REGISTER requests that are sent. The IP to which the VoIP server sends incoming phone calls for Enterprise Alert is often configured statically in the VoIP Server.
    6. When Enterprise Alert connects to the VoIP server it can authenticate via Digest Authentication (from HTTP) with MD5 hashes.
    7. Enterprise Alert does support SIPS, which means it does support encrypted SIP.
    8. Call forwarding (e.g. for the “Call the on-call person” scenario) can be done via “Attended Call Transfer” (http://www.in2eps.com/fo-sip/tk-fo-sip-service-05.html) if supported by the VoIP Server. If Attended Call Transfer is not supported, Enterprise Alert can stay in the line between both people and mix their audio packets together so that they can hear each other. This option would always be available with Enterprise Alert, but it also adds more network overhead. If you have the option, we recommend using Attended Call Transfer since the parties that are connected by Enterprise Alert can continue talking individually once Enterprise Alert has left the call.
    9. Phone conferences are managed entirely by Enterprise Alert at the moment. This means that established conferences are not handed over to the VoIP server with SIP REFER request(s).

    Audio

    1. The supported audio codecs are G711 a-law or u-law as specified below:
      1. PCMU (µLaw), Sample Rate: 8000Hz, Channels:1, 8Bit/Sample
      2. PCMA (ALaw), Sample Rate: 8000Hz, Channels:1, 8Bit/Sample
        These codecs are proposed in our SDP. Other codecs are not supported.
    2. Audio is encoded and transmitted with the Real-time Transport Protocol (RTP).
    3. SRTP (Secure Real-time Transport Protocol) is supported by Enterprise Alert

    Ports

    The following VoIP related ports should be opened for Enterprise Alert in your firewalls:

    1. Signaling: Open the standard VoIP port 5060 for SIP and configure that port in Enterprise Alert as “local listening address”. Otherwise Enterprise Alert will listen on a random allocated port (which can make sense when connecting as phone endpoint).
    2. Audio (RTP): RTP ports are allocated dynamically by Enterprise Alert with each phone call within the configured Port range. The range is different for each VoIP channel that you create in Enterprise Alert. The first VoIP connection starts on port 25500, the second from 26000, the third from 26500 and so on. Each connection then increments the port per phone call is performs. The first call on the first VoIP channel would be done on 25500, the second call on 25502, the third on 25504 and so on.
      We recommend that you whitelist the RTP protocol in your firewall for Enterprise Alert completely as it might be difficult to allow it on a port basis.

    Incoming phone calls to Enterprise Alert

    Incoming phone calls to Enterprise Alert must be deployed in the VoIP system to which Enterprise Alert connects. The idea is to define phone numbers in the VoIP server that can be called to reach Enterprise Alert. The VoIP server forwards all incoming call requests (targeted to the phone numbers or extensions registered for Enterprise Alert) to the corresponding VoIP connection in the Enterprise Alert server. When you work with cloud-based VoIP gateway providers, each inbound phone number usually costs some money. However, the more phone numbers you have for Enterprise Alert the less phone menus Enterprise Alert may need to present when being called. Scenarios could be bound to a phone number directly e.g. if you want to call the on-call person of a specific team, it should be sufficient to call a specific extension or phone number to get connected via Enterprise Alert. On the other hand, if you only have one phone number for Enterprise Alert, you would need to tell Enterprise Alert which on-call person you want to get forwarded to by entering a team code on your phone’s key pad.

    VoIP Servers or Cloud Gateways integrated with so far

    Finally I’d like to list some VoIP systems that we have had good experiences with so far (many thanks to my colleague Hanno from the Derdack Support Team):

    • Cisco Unified Call Manager 8.x or higher
    • Avaya Aura Communication Manager (e.g. R016x.02.0.823.0 AVAYA-SM 6.2.4.0.624005)
    • OmniPCX Enterprise Communication Server (e.g. R10.1.1 j2.603.24)
    • Siemens HiPath (3000 and 4000)
    • Unify OpenScape Voice
    • Mitel-3300-ICP (http://edocs.mitel.com/UG/EN/NAV_33_UG_R1_EN.pdf)
    • placetel (German cloud based VoIP provider: http://www.placetel.de/)
    • Skype Connect (International cloud based VoIP provider: http://www.skype.com/en/features/skype-connect/)
    • Virtual-Call (International cloud based VoIP provider: http://www.virtual-call.com/)

    Tagged

    phoneVoIP

    Share

    Related Posts

    Enterprise Alert 9.4.1 comes with fixes and the revised version of the sentinel connector app

    February 1, 2023

    Critical System Alerts via SIGNL4

    December 29, 2022

    Enterprise Alert 9.4 Update introduces Remote Actions for hybrid scenarios and proxy support for MS Teams

    October 25, 2022

    Upgrade your shopfloor alerting with Derdack

    September 8, 2022

    About

    DERDACK products combine automated alert notification workflows, 24/7 duty scheduling, ad-hoc collaboration and anywhere IT troubleshooting – reducing unexpected IT downtimes at large enterprises and organizations by 60%.

    Most popular

    • Derdack Company Take your ITIL incident management to the next level with Enterprise Alert
    • Mobile alert notifications for HP Service Manager (HPSM)
    • How to forward alerts to Microsoft Teams
    • Oncall Scheduling On-Call Schedule Management with Auto-Rotation
    • Even, Alert, Incident, Notification Definition of Event, Alert, Incident and Notification
    • checking-mobile Enhancing SCOM alert notifications
    • Announcing Enterprise Alert 2019
    • who-is-on-call-sharepoint Add a live “Who is On-Call” Dashboard into Sharepoint and other Tools

    Categories

    • Business (37)
    • Cloud Services (5)
    • Consultancy (1)
    • Customers (18)
    • Energy & Utilities (7)
    • Events (23)
    • Financial & Banking (4)
    • IT Ops (19)
    • Manufacturing (8)
    • News (48)
    • Schools (1)
    • Software (9)
    • Staffing (1)
    • Support (4)
    • Technical (141)
    • Transport & Logistics (5)

    Tags

    alert alert notifications Anywhere Resolution Anywhere Response Azure azure BMC customer reference Database derdack enterprise alert Enterprise Alert Enterprise Alert 2016 Enterprise Alert 2019 Gartner HPE HPE ITSM incident Incident Management Incident resolution incident response Industrie 4.0 Integration IT Alerting IT Operations Maintenance microsoft mobile Mobile App monitoring OMS on-call on-call schedule Operational Alerting rapid response release Remote Action REST API SCOM security SolarWinds NPM System Center update User Group voice

    Follow us

    • Twitter
    • Facebook
    • LinkedIn
    • XING
    • YouTube
    • Vimeo
    • Home
    • News & Blog
    • Technical
    • All about Phone Calls in Enterprise Alert: VoIP Requirements and Capabilities

    CONTACT US:
    Intl: +49 331 29878-0

    US: +1 (804) 212-2278
    CH: +41 (31) 5391990

    CONTACT VIA EMAIL:
    info@derdack.com

    OFFICES:
    US & Europe

    NEWSLETTER:
    Sign up here

    CAREER:
    Latest job offers

    EVENTS

    • No Upcoming Events
    • Who we help
    • Products
    • How to Buy
    • About Derdack
    • News & Blog
    • Free Trial
    • Twitter
    • LinkedIn
    • YouTube
    • Vimeo

     © 2025 Derdack – Imprint, Privacy policy

    • Use Cases
      • Overview
      • Enterprise IT Alerting
      • IT Managed Services
      • Mobile Alerting in Manufacuring
      • Critical Operations Alerting in Banking & Financial
      • Field Service Dispatching in Energy & Utilities
      • Use Cases in other Industries
    • Products
      • Overview
      • Enterprise Alert®
        • Overview
        • Alert Notifications
        • On-call Duty Scheduling
        • Collaboration
        • Anywhere Remediation
        • Incident Mgmt. App
        • Integrations
        • Technical Support
        • Online Knowledge Base
        • Derdack FAQ
      • SIGNL4® Cloud
      • References & More
    • How to Buy
      • Overview
      • Pricing and Quotes
      • Azure Marketplace
    • About Derdack
      • About
      • Careers
      • Strategic Partners
      • Derdack Podcast
      • Contact Derdack
    • News & Blog
    • Request Demo
    Manage Cookie Consent
    We use cookies to optimize our website and our service.
    Functional Always active
    The technical storage or access is strictly necessary for the legitimate purpose of enabling the use of a specific service explicitly requested by the subscriber or user, or for the sole purpose of carrying out the transmission of a communication over an electronic communications network.
    Preferences
    The technical storage or access is necessary for the legitimate purpose of storing preferences that are not requested by the subscriber or user.
    Statistics
    The technical storage or access that is used exclusively for statistical purposes. The technical storage or access that is used exclusively for anonymous statistical purposes. Without a subpoena, voluntary compliance on the part of your Internet Service Provider, or additional records from a third party, information stored or retrieved for this purpose alone cannot usually be used to identify you.
    Marketing
    The technical storage or access is required to create user profiles to send advertising, or to track the user on a website or across several websites for similar marketing purposes.
    Manage options Manage services Manage vendors Read more about these purposes
    View preferences
    {title} {title} {title}