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Working from home enables Sharpen users with the flexibility they need while still being connected to the Sharpen environment. With that flexibility comes additional areas of focus to allow for a consistent experience. Most importantly, it is important to remember that Sharpen is a real-time communications platform assuming prompt and consistent network and workstation availability to support the real-time transmission of audio.

  • SIP ALG - Present in many is enabled

    • Perhaps contrary to its name, SIP ALG is not compatible with most enterprise VoIP solutions, such as Sharpen. Depending on the manufacturer, network device configurations

    as SIP ALG, SIP, VoIP, settings which enable SIP ALG are contrary to a successful network setup with multiple VoIP devices

    • will show up as “SIP ALG”, “SIP”, “VoIP”, or something similar. Intermittent disconnection, dropped calls, one-way audio

    drops

    • , and the inability to register are common symptoms when SIP ALG is enabled.

    This must be shut off for optimal performance.Sharpen strongly discourages the use of “combination” network equipment such as all-in-one modem/router devices. ISPs typically provide or rent these out to customers. They are known for having issues with VOIP traffic as well as having limited access to critical settings. If you are using a combination device and experiencing issues, the first step is to acquire a stand-alone modem and router. 

    • Depending on your device manufacturer or ISP, it may be difficult to get a straight answer on confirming this setting is off. Commonly, ISPs will have this setting enabled, because it supports their own options for VoIP solutions. It is not uncommon to have to work through a couple layers of support or technical team members to validate the proper setting is turned off. 

  • UDP timeout is set less than 240 seconds

    • Sharpen’s expected SIP registration interval is 4 minutes (240 seconds). If your network is set to “timeout” UDP connections at less than that, it will disconnect an active registration. Depending on when this happens, you’ll see the following symptoms.

      • Dropped calls

      • Inability to be reached on the phone which has lost its connection. 

      • You’ll be able to dial outbound without issue, since registration is established on an attempted outbound call, if it does not already exist. 

      • You’re probably seeing a sawtooth pattern in your latency graphs.

  • ISP provided “combination” network equipment

    • Especially if you’re working from home on your residential internet connection, be weary of the Internet Service Provider (ISP) controlled settings which may exist on these managed devices. “Combination” devices are typically those which integrate modem, router, and wifi into one device. While in principle, the integration of these functions problematic, they can sometimes come with configuration hurdles which are difficult to overcome since you, as the borrower of the device, do not have administration access to the devices. It is not uncommon for settings like SIP ALG to be enabled but invisible to you as the user. These situations require that you work with your ISP’s support team to change a setting. 

    • As a result, Sharpen discourages the use of combination network equipment. Instead we recommend purchasing a stand alone modem which is compatible with your ISP, and connecting a router of choice to it. This allows you full control of any potentially conflicting setting. Most self-managed devices have these problematic settings disabled by default.

    • If you can not acquire a stand-alone modem and router, we recommend reaching out to your ISP to see if they can place your combination device in “bridge” mode, then purchasing and connecting a 3rd party router to handle the local networking. 

  • Ensure UDP timeouts are greater than 240 seconds (phones register every 240 sec). If you’re seeing a sawtooth pattern in your latency graphs, or your phones are sometimes unable to be reached, the UDP timeout is probably incorrect.

  • Disable Stateful Packet Inspection (SPI) as it often flags VOIP traffic incorrectly. 

  • Disable any VOIP specific functions that come pre-setup on your network equipment.

  • Sharpen traffic over a VPN is discouraged due to likely latency and quality of service concerns.

  • Sharpen traffic over an MPLS is discouraged due to potential inefficient route paths to voice resourcesVPN

    • VPNs have many valid use cases, especially for work from home users. However, VPNs are not always configured to be optimal for voice traffic. Adding the additional virtual layer to the network, in most situations, will cause a recognizable degradation in network performance. Voice requires low latency, with minimal packet loss. As a result, if the VPN introduces too much interruption, your quality of service will be impacted. If VPN is necessary, it is recommended to configure it so Sharpen traffic can be omitted through the us of split tunneling.

Ports and Protocols

While most work-from-home users will be all set, it is important to make sure the following ports/protocols are free to communicate with our environment. If, for some reason, your ISP has restricted activity on these ports, you'll need to work with them to allow two-way traffic.

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