1) I can do 33.6K with my PM3's.
2) Home many times have you had to hot swap out digital modem cards? Me?
None! Or are you telling me I should be ready to hot swap out USR cards? Hmmmm
3) You have to swap out the modems to upgrade to 56K? So what? It's a
free upgrade for Livingston and it takes two seconds!
on and on and on... I'll stop here, I don't have time to correct someone
who should know better!
Dave...
------------------------------------
P.S. In case you think you are convinced that the Portmaster 3 is what you
want, think again. I have been a Livingston fan for years, and the
portmaster 3 looks promising but is the new kid on the block and it's not
all sunshine. Here is some info you should consider below, namely you only
get 28.8 today, and you must change out EVERY modem to get 56K when it's
available.
************************* Portmaster 3 info
**************************************
Strategy for Supporting 56K Modem Technology
Livingston touts their digital modems, which are based on an Analog Devices
DSP platform, in part because it frees them from analog-to-digital
conversions required by modem chipsets. The issues are ones of ownership
and understanding of the source code used to drive the Analog Devices
engines. As signaled by Livingston's partnership with Lucent Technologies
to acquire 56Kbps code when available from Lucent, Livingston doesn't
really understand the key element to their PortMaster 3 product - the modem
technology. There's also the integration and test aspects of incorporating
new software into the modem cards and the internal expertise you need to
accomplish that task reliably. The issue it comes down to is: U.S. Robotics
owns the modem code and the intellectual property that goes with that
ownership; Livingston does not.
No 33.6Kbps Modem Support Today
Again, because Livingston does not take ownership of their modem
technology, the PortMaster 3 modems only support 28.8K today. There is no
support for 33.6K (V.34+) technology.
Hot Swappability Caveats
Although the PortMaster 3 claims the modem cards are hot swappable,
customers have to do so from the back of the unit. In contrast, for a Total
Control Hub with a digital interface (T1 or T1/PRI trunk), only the modem
NACs are required and those are accessible form the front of the chassis.
In short, the Total Control Hub is far more maintainable than the
PortMaster 3.
Very Limited System Modularity and Expandability
In the PortMaster 3, system expandability and upgradability is limited
solely to modem card updates. The gateway, router, management and trunk
interface functions are all integral to the system and cannot be migrated
to new platforms in the future. Thus, the deployed infrastructure of
Livingston PortMaster 3's would require fork-lift upgrades for those
customers seeking to migrate to higher system densities, new gateways,
enhanced router engines or the like. For example, the PortMaster 3 utilizes
an Intel 486 microprocessor running at 66MHz for routing as well as main
system processing. While this may be fine for today's system requirements,
there is no method to upgrade this processor engine without replacing the
PortMaster 3 case with whatever next generation product Livingston develops.
No Support for VPNs
Internet Service Providers can support virtual private networks, or VPNs,
to corporate customers looking to save the costs of dedicated trunks via a
variety of tunneling protocols. The Total Control Hub supports one such
tunneling protocol today, PPTP, with development underway to support the
L2TP standard in the future. In contrast, the PortMaster 3 offers no VPN
tunneling protocols today.
Reliability Issues
System reliability is clearly an issue. First, Livingston does not test to
or support Bellcore's NEBS (Network Equipment Building System)
requirements. NEBS criteria are used to evaluate a product's physical
characteristics, and its ability to operate as intended under electrical
and physical environmental stresses, such as electromagnetic interference,
high and low temperatures, earthquake, and vibration conditions. It is also
used to assure that equipment does not pose a threat to service or
personnel, via analyses for fire resistance, electrical safety and
grounding. These standards are most relevant to the telcos, but their
fundamentals are of benefit to all customers by ensuring improved safety
and reliability.
Also, the PortMaster 3 does not support power supply redundancy nor can it
support gateway redundancy; instead they rely on a single power unit and a
single gateway respectively. In short, the PortMaster 3 is open to single
points of failure. While they admonish the system's ability to re-route
modem traffic from a bad modem port to avoid failure, they fail to provide
that reliability at a system level. In contrast, the Total Control Hub is
modular in design and can thereby be configured to support system
redundancies and thereby eliminate single points of failure.
Finally, the common equipment on the PortMaster 3, such as trunk interfaces
and management functions, are not serviceable. A failure of those
components requires the customer to reinstall and then re-cable a
PortMaster 3 in the event of failure. Even a fan failure will require this
arduous task. Again, the modularity and total hot swappability of all
system cards avoids this unnecessary work and down-time.
WAN Interface Shortcomings
A real problem with the PortMaster 3 is highlighted when a customer wants
to support frame relay at the egress of the system as opposed to 10Mb
ethernet. With frame relay in the PortMaster 3, the customer must consume
one of the only two T1/E1 ports, thereby reducing total system channel
support to only 24 modems instead of 48 modems. In the Total Control Hub,
frame relay is supported via a dedicated 1.024Mbps V.35 interface,
preserving chassis capacity.
Livingston Customer Service and Commitment Issues
Livingston is a privately held corporation who first started to get into
the remote access market in 1990. In addition, their current sales channel
is direct and they claim to service over 1,500 ISP's. One has to wonder
about the level of customer service and commitment from a small independent
company looking to support them with a small direct sales and service staff.
System Management Issues
Network management for the PortMaster 3 is limited to PMconsole,
proprietary Livingston management utility software used to configure and
control the PortMaster and IRX products. PMconsole provides a graphical
user interface and is usable from any TCP/IP or IPX workstation. It is
available for the MS-Windows, Sun Sparc, DECstation, IBM RS/6000 and HP9000
platforms. Because PMconsole does not support the more ubiquitous
management and accounting utilities like HP OpenView and SunNet Manager,
the PortMaster 3 limits the options for the network operators and the
environments under which they can manage the Livingston system.
Another shortcoming is the PortMaster 3's current inability to support
modem status via the GUI. This clearly hinders performance monitoring and
system maintenance for the network operator.
Finally, the PortMaster 3 lacks auto response capabilities, a script
management feature supported by the Total Control Hub which allows the
system to be configured to automatically respond to system-detected network
problems without operator intervention.
No EdgeServer
The ability of the PortMaster 3 to support Level II EdgeServer capabilities
is also lacking. This is an issue for corporate customers or service
providers who support an NT operating environment and are looking to
integrate RAS capabilities.
Looks like the PM3 has limited T1 support today
According to a Livingston note on the PortMaster 3, they indicate that the
product currently does not support dial-up signaling over channelized T1.
Although it is not clear exactly what that means, it sounds like a
potentially major problem for customers. With a definite limitation
regarding the system's support for digital T1 interfaces, this is a real
problem for a product which is designed with those interfaces in mind.
No support for analog dial-up
The PortMaster 3 only offers support for T1 or T1/PRI digital trunk
interfaces. The system does not offer support for individual analog dial-in
access over POTs. For those customers looking to start small with a modem
pool application and then easily and economically migrate to digital trunks
as their business grows, the PortMaster 3 fails to offer this level of
flexibility.
No front panel indicators to help with system troubleshooting
The lack of front panel indicators on the PortMaster 3 will present some
real problems for site installers and engineers looking to isolate system
problems without first accessing the system management interface. Front
panel LEDs on the Total Control Hub provide a wealth of information at a
glance.
Thank you for working with Capella Worldwide Networking, Inc.,
"Internetworking Specialists" TECHNOLOGY TO THE PROVIDERS
Gregory F. Genge, President; Capella Networking Canada, Inc.
VP of Sales, Canada; Capella Worldwide Networking, Inc.
Toll Free 888-ALLEPAC, 888-255-3722
(403) 571-5000 Main, 5003 Direct, 5005 Fax
832 Durham Avenue S.W., Calgary, Alberta, Canada, T2T-5R2
Email: ggenge@capella.com Web page http://www.agt.net/public/capella/
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| Dave Berzins, President Nucleus Inc. 1835B 10 Ave S.W. Calgary, AB, T3C 0K2|
| 403-209-0000 Voice, 403-541-9400 Modem, 403-541-9474 Fax |
|email:berzins@nucleus.com www: http://www.nucleus.com finger:nis.nucleus.com|
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