Cisco IOS Solutions for Voice Gateways
To select voice-capable hardware is not enough.You must also choose the correct
IOS firmware for the gateway router so the gateway can speak the proper voice
lingo to CallManager. Savvy network designers use all facets of the Cisco Web
site to learn as much as they can about the products so they can choose the
proper equipment.This portion of the Cisco Web site is called “Cisco
Connections Online” or CCO for short. Access to CCO requires that you have
an account with Cisco to access this private area.This account is usually granted
for customers that purchase the SmartNet maintenance when they purchase their
Cisco products. CCO grants you access to special areas of neat documents, technical
tips, and tools for searching the feature sets of IOS versions.
To find the Cisco-approved IOS for our small site, we go to the Feature
Navigator in Cisco’s Web site. For our small site, we’ve chosen the 1750 as our
voice-capable gateway. In Feature Navigator, we first had to type in the feature
we wanted, which is Media Gateway Control Protocol (MGCP).When MGCP
was typed in and the search began, we were presented with four optional results.
One was the 1750 voice-capable gateway and the other was MGCP support for
CallManager on other gateways like the VG200 and 2621 routers.
We then selected VoIP signaling for the 1750, and told the Web site to continue.
What we got next was a set of dropdown menus to begin narrowing down
the choices. Clicking the release drop-down, we see that there are only two possible
IOS choices, both in the 12.2 family for the 1750 gateway.We chose the
12.2(2)T family, the T meaning “technology” IOS.The T code has all of the
newest features such as VoIP, but requires much more memory and flash than
does say the plain IP-only IOS. In the platforms dropdown, we chose our 1700
family of gateways, and lastly chose the IP/ADSL/VOICE/Plus code.
Even though we won’t use the ADSL portion of the code, ADSL is included
with all 1700 Series gateways.This yields the following IOS for us to order with
the new gateway:
C1700-sv3y7-mz.12.2-2.T
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This is the easy way to find the Cisco-approved IOS for your site.We could
do much the same thing for say a 2621 router, but in Feature Navigator choose
the MGCP support for CallManager. After choosing the MGCP Support for
CallManager and going to the platform family, notice that the choices are much
different. Among the possible voice-capable gateways are the 2600, 3600, ICS
7700, ubr905, and the VG200.The first three selections are families of gateways
while the last two are individual devices. Also apparent is the slimmed down
choices of IOS versions since we’re looking at voice. Regardless, we’ve now
selected the correct Cisco-approved IOS for our new voice gateway.