Security Sales & Integration April 2021 - 38

Access
Your OSDP
Need-to-Know

Compared to Wiegand, which
offers simple point-to-point topologies, OSDP offers point-topoint and multidrop. Of course,
multidrop also means individually naming, or addressing, the
readers in the system.

in terms of security and functionality.
It helps ensure that numerous manufacturers' products will work with each other. Interoperability can be achieved regardless of system architecture. For instance, the specification
can handle smartcards by constantly monitoring wiring to protect against attack threats and
serves as a solution for high-end encryption
such as required in federal applications. The
specification for handling LEDs, text, buzzers
and other feedback mechanisms provides a
rich, user-centric access control environment.
To again emphasize, OSDP provides the option for encrypted channel communications.
Wiegand does not. Known as a secure channel,
OSDP lets communications traffic between a
reader and controller be encrypted. Specifical-

ly, this traffic can be encrypted via Advanced
Encryption Standard (AES) with a 128-bit key.
This is real encryption, not just a data scramble. AES is itself a recognized and widely adopted specification for the encryption of electronic
data established by the U.S. National Institute
of Standards and Technology.
OSDP provides two-way communications.
Wiegand is a one-way street for data. For example, this lets the reader be queried as to its status.
Think of this as a health check. It's standard with
OSDP, but not that easy to do with Wiegand.
OSDP riding on RS-485 provides longer
cable runs while Wiegand is shorter. OSDP offers optional configurations of wiring topology
while Wiegand only offers one. This flexibility
can be very beneficial in minimizing installation and retrofit operations.
Wiring requirements are also different. An
OSDP cable only requires four conductors.
Wiegand cabling may require five, or even
more, conductors. This makes them larger,
heavier and, often, more expensive.
Finally, OSDP lets the data rate be adjusted. With Wiegand, that is not the case. The
advantage is that larger quantities of data can
be transmitted quicker with OSDP. Think of a
personal identity verification (PIV) card. This
data could be transmitted in less time than it
would take with Wiegand.

WEBHOOKS EMPOWER EXPANDED INTEGRATIONS By Evan Tree
▶ It's said that change is the

only constant. For those who
work with access control, that
maxim has never felt more
true. Cloud and mobile platforms are quickly becoming
standard in the industry, allowing users to interact with
their access control in ways
never before possible.
Behind-the-scenes integrations among Cloud platforms
allow data to be exchanged,
further lightening the burden
from users of these platforms. As the sophistication
of these integrations grows,
so does the need for the platforms to quickly notify each

other of changes. These notifications have been standardized as " user-defined HTTP
callbacks, " or as they're more
commonly called, webhooks.
Before webhooks became
standard, integrations often
exchanged information by
blindly copying over every
piece of information in one
platform to the other whether
or not it was needed. Why?
It was because the platform
sending information was
completely in the dark about
what the other platform finds
important.
While this arrangement
works in principle, it quickly

38 Security Sales & Integration APRIL 2021

SS2104 pp36-40 OSDP.indd 38

becomes unsustainable as
the information contained
in each system grows. To
combat the growing expense
of this data transfer, these
integrations are often limited
to only transferring information perhaps once an hour, or
in extreme cases, once a day.
Webhooks overcome
these problems by creating
a standard way for platform
A to explicitly tell platform B
what information A values.
Platform B will then notify
A when the information A
values becomes available.
This principle should be
familiar to any parent with

a child repeatedly asking,
" Are we there yet? " on a road
trip. Fortunately, computers,
unlike children, are perfectly satisfied to hear the
response, " I'll let you know
when we're there. "
These requests to be
notified are called subscriptions. They contain a list of
events for which the receiver
will be notified, and to which
HTTP endpoint they will be
delivered.
Once a subscription is established, events will immediately begin flowing as they're
regenerated with no need to
renew the subscription.

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3/22/21 10:29 AM

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Security Sales & Integration April 2021

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