1493284664645476.jpg +86 075561882266    1493284683105363.jpg  +852 21357223 


Home > Services & Products > Voice Services


    LINK-AZ offers carrier-grade SIP trunking service for IP-PBX systems and analog/digital telephone adapters. LINK-AZ provides a reliable network, easy on-demand service, and flexible connectivity options.

    1. Detail info

    Hong Kong SIP

    Scale your voice services, without breaking the bank

         LINK-AZ offers carrier-grade SIP trunking service for IP-PBX systems and analog/digital telephone adapters. LINK-AZ provides a reliable network, easy on-demand service, and flexible connectivity options.



    Inbound and outbound voice capabilities

          Always have a clear, reliable, and high-quality connection with LINK-AZ's cloud-optimized communications services.


    • Inbound SIP trunking / origination

         LINK-AZ’s inbound SIP trunking provides unlimited concurrent call capacity. With no limitations or restrictions, you can say goodbye to capacity planning. As your volume increases, new instances are dynamically created to help you scale your voice services.


    • Outbound SIP trunking / termination

           LINK-AZ delivers outbound call audio over the shortest path possible to increase call quality and lower call costs locally and internationally.



    Purchase local, toll-free, and vanity numbers in US and Canada

          Have an existing phone number? Discover what makes LINK-AZ truly unique by way of its in-house porting team and proprietary customer onboarding process.


    • Local phone numbers

    Select local telephone numbers by area code in any location across the US & Canada.


    • Vanity phone numbers

    Choose a unique phone number that makes sense for your business from LINK-AZ's large inventory of vanity phone numbers.


    • Toll-free phone numbers

    Choose from a large selection of toll-free numbers including (800), (888), and (855).


    • Port existing phone numbers

    LINK-AZ has made customer onboarding more predictable and transparent by reducing the complexities that surround the porting process.




    Your security is our top priority

          LINK-AZ provides account level protection to mitigate your risk of toll fraud and to further secure your business.


    • Disable outbound SIP credentials

          Enable IP-based authentication to place outbound calls from approved IPs.

    • Maximum outbound rate

          Block any outbound call if it exceeds a rate you have predefined in your online portal. 

    • Destination restriction

          Manually blacklist destinations to ensure no traffic is ever being sent to undesired destinations. 

    • Destination whitelisting

          Just starting out with Flowroute? Utilize destination whitelisting so we can learn your traffic patterns to proactively fend off potential fraud in the future.

    • International toll fraud protection

          Monitor for international call fraud and take immediate action to kill unauthorized calls on your trunk and alert both you and Flowroute's DevOps team of suspicious activity.


    Technical specs


    • G.711:Standard audio compression

    • G.729:Efficient audio compression

    • T.38:Reliable Fax-over-IP support on calls



    • SIP over UDP:Supported

    • SIP over TCP:Supported



    • DTMF:RFC 4733, RFC 2833

    • Caller-ID (CLI):P-Asserted-Identity, privacy support

    • Forwarding:Diversion headers

    • Custom Tags:X-Tag header

    • ANI-II / OLI :ISUP-OLI headers




    Improve your voice capabilities with custom account presets 

    Flowroute offers extended account functionality to enhance your voice services.



     Easily enable Caller ID on all of your Flowroute DIDs. Our Caller-ID name storage is a free service that allows you to associate a 15 character name with any Flowroute phone number on your account. It's a proven fact, calls that display a name, as well as a number, receive significantly higher answer rates.



    Emergencies happen, and that is why with Flowroute’s Enhanced 911 (E911) service, you can easily attach a US or Canadian address to any Flowroute number, making sure emergency services knows where to send help as soon as your call comes in.


    • The largest E911 coverage in the US and Canada

    • Eliminate dedicated 911 trunks

    • Replace regional PS-ALI accounts

    • No more managing emergency locations

    • Identification numbers