Open Source Telephony Journal

Callcentric has just been added to my list of providers.  Despite an initial problem things are now swimming on a 1.4 PIAF install.  Callcentric has earned a good reputation for themselves in a few of the VoIP forums.  According to what some of the users have posted, quality and service are quite high.  Callcentric reminds me of, and seems to share a model that's a bit like VoicePulse's aproach as a provider.  They aren't the cheapest and don't have the biggest feature set, but are very committed to delivering a quality level of service and reliability.

They own their own SS7 equipment and pass calls directly onto the PSTN network- a plus.  They offer both residential and business service, including a pay-as-you-go plan and wholesale services.  The web portal is functional and easy to navigate and the rates are reasonable.  They offer BYOD and Asterisk support using SIP (no IAX support).  Features are most impressive with BYOD plans as they have an extensive routing customization they refer to as 'call treatments', which replicates Asterisk's call handling functions to a degree.  They are currently set as an outbound provider, no DID, so I can't comment on the inbound routing features first hand. 

911 is a requirement if you are in the US & Canada, regardless if you have a DID with them or are using it for outbound only.  This unfortunately means some recurring fees.  It's $3.00 to start (911 setup & first month), and $1.50 per month going forward.  I have PSTN primarily for fax, but also to handle 911 calling.  This makes it a waste for me, but I understand the nature and risks involved for ITSP's and Callcentric was clear about this fee up front.  One possible concern to some is the 2 hour call limit.  After 2 hours calls are disconnected, while not a problem for most users, it's something one should know.

Onto the setup.  Callcentric has an extensive list of setup guides for hardware devices, softphones, and PBX software.  I added Callcentric to an existing PIAF (PBX-in-a-Flash) 1.4 server with freePBX version 2.6.0RC2.  The dated instruction set for freePBX/Trixbox was the best match and was used as a template for getting things working.  Unfortunately it didn't, at least for me.  Following the guide, the trunk settings they listed resulted in rejection (INVITE) errors when passing an outbound call to them.  After some elbow grease, I was able to resolve this using these settings in the peer details of the outbound settings within Callcentric's trunk:

username=1777XXXXXXX
type=peer
secret=SECRET
qualify=yes
insecure=port,invite
host=callcentric.com
fromuser=1777XXXXXXX
fromdomain=callcentric.com
dtmfmode=rfc2833
disallow=all
context=from-trunk
canreinvite=no
allow=ulaw
nat=yes
sendrpid=yes
trustrpid=no

Hopefully they'll update their guide to reflect what are probably both changes in Asterisk and changes they've made.  I need to explain the last two lines, sendrpid & trustrpid.  Those allow passing of a custom outbound CID.  I'll explain further as outbound CID with Callcentric is a little tricky.  Callcentric doesn't give you permission to pass any outbound CID.  If you have a non-Callcentric DID that you'd like to pass as the CID, as I do, then you first have to get the number you wish to pass verified.  Verifying a number is well documented and easy to do.  Once verified, the number can be added to the outbound CiD field of the Callcentric trunk.  With the addition of the sendrpid and trustrpid settings (above) in the outbound peer details, Callcentric will then pass the CID.

What's my opinion right now?  So far, so good.  After a couple of weeks I'll be in a better position to comment on call QoS.  I will say that so far the couple of dozen outbound calls have been quick to connect and meet expectations.  Look for a future update.

[Update]Further proof of the existence of Murphy's Law- The day after the original post, Callcentric had a hard outage (10/01) taking down calls, failover, even their website.  The total outage lasted about 1.5 hours, and it was determined to be a capacity issue that planned hardware upgrades will resolve early on Oct. 5th.  Outages have been an extremely rare event for Callcentric, and I expect will continue to be rare post upgrade.