Authors Mark Lindsey
SMTS at ECG


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 professio...


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 th...


Gamblers and Preppies

In VoIP Carrier networks, as in other complex systems, there are two types of problems. I'll call these "Preppy" problems, and "Gambling" problems. Preppy problems occur when you're at the limits of achievable quality within the tolerable costs. -- A physical device fails.-- A generally good algorithm has a memory leak.-- A hacker finds a way to exploit a defect in your firewall. -- VoIP throu...


FraudStopper Frequently Asked Questions

Here at ECG, we're very excited about FraudStopper, our toll-fraud detection system. It is the only Fraud Detection tool optimized for VoIP service providers running BroadWorks, Metaswitch, or similar platforms. You can get more details on FraudStopper on the FraudStopper page.   Here are some of the common questions we're getting. What kind of fraud does FraudStopper stop? Fra...


Meaningless telecom statistics are a pain in the asr.

In the 1960s, General Telephone and Electronics Corporation, GTE, employed my father to visit their Central Offices in Georgia to connect measurement equipment to their telephone switches. The purpose was to monitor the system for evidence of problems. They came up with all kinds of measurements in that era; one of the most enduring was Answer-Seizure Ratio, ASR. The ASR is 100*(number of call...


GrandStream GXP-2100: A step in the right direction

I once frustrated the Grandstream marketing folks at a tradeshow. The year was around 2007, and the show was SuperComm. (I think.) My exposure to GrandStream was the BudgeTone and the HandyTone. We had tested both devices, and made them work, but neither of them was something we could recommend. I asked the booth-staffers whether they had any business phones. They pointed at something with nov...


What's Driving SBC Growth?

Seven years ago I sat down in a cramped office outside Boston. I was visiting Acme Packet, and the question on everyone's mind was this: How long will this "SBC" thing hold out? You see, in 2004, everybody I talked to about the Acme Packet thought it was a temporary fix to a technical oversight. Maybe the SIP people would modify the standard to accommodate NAT and Firewalls better. Or perhaps ...


When will my SBC Be Out of Gas? Predicting Signaling Element Maximum Capacity

When will my Session Border Controller be "full"? The same question applies to any other signaling element in a VoIP network: how much more work can I put into this device before it's overloaded? In this discussion, we'll focus on the Acme Packet OS-C Session Border Controller, such as the NN4250 or NN3820. The typical constraints people bump into are CPU usage and session licenses. Predicting...


New Podcast: Samuel Rausch of Comcast: Engineering SIP Timers End-to-End for Optimal Network Performance

At the SIPNOC 2011 Conference held 2011 April 26-27 in Reston, Virginia, Samuel Rausch of Comcast spoke about their project tuning SIP Timers to improve failover performance in their network. They were able to successfully make network faults invisible by tuning the timers appropriately. I sat down with Samuel during a break in the conference and recorded a short interview on his presentation...


Cisco Pricing: Easier to get than ever.

Cisco has made it much easier for engineers to properly account for costs when evaluating alternatives and options. They've published a very extensive list of product part numbers and retail pricing. The standard way to estimate pricing on larger items (like routers) involves a long and arduous back-and-forth with a Cisco reseller. The reseller does help by configuring the proper combination of...


Do Telephone Companies Actually Matter Any More?

Note: The following essay was adapted from a talk I gave to staff at Earthlink Business in January 2011. Do we really need telephone companies, or are they a relic of the past technology, now replaced by data networks? I had this question upon entering the voice side of the Networking Industry, coming from classical Computer Science and Data Networking. Technology history had shown that c...


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...


Metaswitch pitches DC-SBC; should Acme Packet be afraid?

Metaswitch has been talking a lot lately about VoIP Session Border Controllers (SBCs). They recently took their DC-SBC product to the SIPit interop testing event in June. And they just published another white paper about SBCs and their role in IMS. The Enfield company formerly called Data Connection Limited definitely makes solid software. Rumor has it some of these gents were hired to make ...


SIP Registration Attacks are Here -- Defend Yourself

A few cases of SIP dictionary attacks using the "friendly-scanner" have been reported recently. These appear to be active attempts to steal service. We responded today to an attack on a nationwide Service Provider. They reported up to 69 REGISTERs per second originating from an IP address in Anhui province, China. 69 REGISTERs per second is roughly the equivalent load of 5,000 users. Unfo...


Defend Your Network against SIP Registration Attacks

A few cases of SIP dictionary attacks using the "friendly-scanner" have been reported recently. These appear to be active attempts to steal service. We responded today to an attack on a nationwide Service Provider. They reported up to 69 REGISTERs per second originating from an IP address in Anhui province, China. 69 REGISTERs per second is roughly the equivalent load of 5,000 users. ...