Tags voip

ECG: Engineering BroadWorks at US Department of Justice

MIAMI, FLORIDA - BroadSoft Connections 2018 - The US Department of Justice (DOJ) has now allowed ECG to publish information about the long-term relationship in which ECG, Inc. has been proudly supporting Federal law enforcement since 2007. This partnership is one of ECG's proudest contributions to reliable communications for critical, life-saving goals. The US DOJ approved release of the info...


Space Probes and SIP Phones: Successful Device Launches with BroadWorks

Careful testing is crucial for stability before launching new SIP Access Device models The Product Definition must be baked into the Test Plan used to approve the device, & new software for it Customer Technical Support teams need extensive early access to devices  before they are deployed Space Probes are designed to be sent far away, beyond our reach. They run software, and send back d...


SIP and Fragments: Together Forever?

IP Fragmentation of SIP Messages is an enduring source of trouble. Fragmentation of SIP traffic is a problem on the rise. It appears when everything has been working fine, and seemingly without cause,  some SIP messages are lost in the network. The result is a frustrating scenario where some SIP messages are delivered fine, but others are not. To explain SIP fragmentation, let's start at the be...


Using SIP to Block Robocalling: On the Telephone, Nobody Knows You're a Robot

Robocalling, enabled by VoIP, causes real social harm Filtering based on Caller ID brings some temporary relief The telecom industry has real work ahead to protect Caller ID with STIR VoIP Drove down the cost of making phone calls. We love that about VoIP: free long distance! In the telecom industry now, the idea that calls within a country would cost a retail user more than local calls seems...


See only a Sampling of RTP frames in a Wireshark Packet Capture

Question: How do you make a display filter that filters out most RTP frames, but leaves a representative sample? Sometimes it's convenient to see a sampling of RTP frames in Wireshark, without having to see 50 per second. Answer: Rather then see 50 frames per second for every RTP flow, how about one frame every 5 seconds? Wireshark display filter: rtp[3:1]==0 or rtp.marker==1 Shows an RTP pa...


SIP Trunking: Public, Private, VPN, and Why

When you're connecting to the rest of the world to make and receive phone calls, you have several design options available. Or, more precisely, your Voice Service Providers have many options available. VoIP via Layer-3 VPN In this case, a Layer-3 VPN, such as MPLS over the Voice Provider’s own equipment, is used to connect a Voice customer to the Voice service provider. Shared infrastructure i...


"URL" Dialing: Calling arbitrary SIP places on the Internet

BroadWorks calls it "URL Dialing": calling from your hosted PBX VoIP phone or SIP Trunking device to a random SIP URI. Lately, Polycom has been handing out SIP URIs and inviting people to test out their video bridges. Let's say you want to call to sip:1234@opensips.org -- how should it work? Most VoIP services providers -- such as those built on BroadWorks and Metaswitch -- don't allow calls fr...


High Performance SIP Trunking / Termination Service using Metaswitch and Oracle/Acme Packet

    Metaswitch and Oracle Communications (formerly Acme Packet) would love to own each other's customers; and many service providers own both. This design shows how the two can be combined to make a scalable, high-performance SIP termination platform appropriate for outbound call centers. High-performance call termination can be a challenge; many conventional systems, rich in SIP trunking feat...


Where is the Demarc in Hosted VoIP PBX?

In telecom, the "demarc" represents the point in the network where the responsibility differs; it is the interface between the service provider and the customer. Traditional Analog POTS: The Demarc is often a test port on the side of the building. If something is broken between the test port and the customer's phone, then it's the customer's responsibility to fix it. Otherwise, it's the servic...


Making VoIP Geo-Redundancy Actually Work Well

Geographic Fault Tolerance for VoIP Carriers is a hot topic. The dream is to offer a telecom service that functions properly, even if half of the equipment is detonated. Fortunately, a VoIP Carrier far more likely to experience a simple network outage due to backhoe fade, or lose a building due to flooding, than they are to be attacked by gamma rays. Reliability is a key goal of professional Vo...


Interest High in VoIP Security at SIPNOC 2012

Large Financial Losses Dominate Concern June 2012, Hyatt Dulles, Sterling, Virginia, USA: Carrier VoIP Security was the first technical topic discussed at the SIPForum's SIPNOC 2012 conference. A standing-room-only crowd of engineers attended an informal Birds-of-Feather (BOF) session on the latest in VoIP Security Threats and Prevention techniques. Dollars Lost, Interest Gained Why the huge i...


Four Predictions about IPv6 for VoIP Carriers

ORLANDO, Metaswitch Forum. VoIP service providers are thinking more about IPv6 every day, based on my requests. Here at the Metaswitch Forum, the UK-based company is dedicating an entire session to IPv6 deployments. They'll be speaking to the 200+ carriers, large and small, assembled at this year's Metaswitch event. The questions we hear are, "How will it affect me? How should I be planning now...


Call Transfer Scenarios in VoIP, SIP, IMS

UPDATED: 2014 October 1: A "Semi-consultative" call transfer cases are now included. The IETF Call Control - Transfer draft seems to have the best and latest info on call transfer scenarios. But I haven't find a good summary of the cases involving transfer-like scenarios. -- Blind transfer, original recipient is facilitator: Alice calls Bob, Bob answers, Alice and Bob talk, Bob transfers to C...


Verizon vs. Vonage on patents -- consensus growing on "direct media" issue

Consensus is growing among some system implementors that Verizon's patents for calling to PSTN and VoIP endpoints is tightly coupled to "direct media". This article discusses the three claims on which Vonage was found infringing and how it relates to other hosted VoIP carriers, like those using MetaSwitch, Sylantro, or BroadSoft. US Patent 6,104,711, Claim 20 talks about making calls directly t...


Is VoIP there yet?

Voice over IP is obviously big seller these days. Everybody wants to do it. But is VoIP really there yet? I mean, can you depend on it the way you rely on traditional telephony? There are some simple reasons to expect not: The systems are all very new. Joel Spolsky makes strong points that it takes about ten years for software to mature to being truly useful. The feature set is very rich, and...