Subject: [Ieprep] commercial SIP service

From: "King, Kimberly S." <[email-masked]>
Date: Fri, 6 Dec 2002 16:12:12 -0500

Worldcom offers IP Communications, a converged voice/data service using SIP
mainly targeted at small to medium businesses.   I contacted them on behalf
of ieprep as a result of last week's discussions and Henry Sinnreich was
kind enough to provide some answers.

They will:

Provision CPE to support a fixed maximum number of voice calls over a
customer access link.  This is based upon policy of UDP to TCP ratios and
also maximum data burst sizes.  What this means is that the customers may
choose more or fewer maximum voice connections (as a function of the link
speed) with the tradeoff of how fast they can send data during times when
all those virtual voice channels are in use.

They use a QoS appliance at the customer premise to track the number of
calls.  (Kimberly note:  These QoS appliances are alternate way that some
consider much easier to use than QoS provisioning of a CPE router.  The
appliances usually sport a GUI interface.) 

They achieve the same call quality when there is an IP-PSTN call. 
And Henry claims IP-IP is better quality than the PSTN, since it is the
ultimate 4-wire link: 
Close to 4 kHz vs. 3.1 kHz (on PSTN), no noise, no distortion, no 
copper-frequency attenuation, no echo, if correctly implemented.  

The service is similar to an IP-Centrix with SIP servers in the Worldcom
backbone providing the call signaling function.

They are not using QoS in their backbone.

They provide a list of firewalls that interoperate with the SIP service.

Most of the 60,000 WorldCom employees have access to the IP phones at their
desks. 

Some employees may also use VPN technology and "take their office phone" to
their new location accessing over the Internet. They can use the SIP 
based Windows Messenger 4.7 or the Pingtel PC soft phones. The narrowband
G.723.1 codec in the Windows Messenger, allows business quality voice calls
over RASNet (UUNet) dial-up to the Internet (such as from hotel rooms). The
Windows Messenger will be part of the Connection early in 1Q03.

Should a "SIP Resource Priority Mechanism" become available, they do not
anticipate difficulties in supporting such a mechanism at gateways to the
PSTN if the market calls for such a need.  This could be a potential
enhancement of the GETS service.  

What would happen if someone dialed a GETS call today using IP Comm?
Either the "shared local gateway" in the WorldCom network, or a physical
local gateway box will connect such calls (911, 800, 411, etc) to the local
phone network.

What types of PSTN signaling are used?  
"Network Gateways" connect to the PSTN using SS7 or PRI, while "Enterprise
Gateways" connect the PBX to the local IP/LAN using Q.931 or CAS signaling. 

- Kimberly

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From: RJ Atkinson <[email-masked]>
Date: Mon, 9 Dec 2002 13:57:00 -0500

On Friday, Dec 6, 2002, at 16:12 America/Montreal, King, Kimberly S. 
wrote:

> Worldcom offers IP Communications, ...

Which part of Worldcom is offering this particular service/product ?
There are many parts of Worldcom, many of which are operated separately
from each other.

For example, is this an MCI service or a UUnet service or an MFS service
or some other construct ?

Does it use the UUnet backbone or a specially-constructed backbone of
some other operating unit of Worldcom ?

Thanks,

Ran