Problems Using the Voice
Gateway for Combined Data Access
Lastly in this section, we shall discuss using one gateway for both data and voice
access.We’ve seen many sites that, because of financial constraints, use the same
gateway for both voice and data services.While the intent is good, the integration
of this idea is usually marginally operative at best.The reason for this is not in
pushing the gateway’s CPU to maximum performance, but rather in running too
many services on the same gateway.At times, the gateway can be confused and
cause reboots at the most inopportune times.This isn’t to say that every site that
uses the same gateway for data and voice will have this problem—far from it—
but you should be keenly aware that this situation might exist. Figure 10.8 shows
the recommended site configuration when this issue arises, regardless of the
amount of users.
The most important idea to recognize in Figure 10.8 is that now the voice is
not only separated by VLAN, but by the gateway as well.We’ve reduced the
overall site cost for electronics by about one third while retaining the equivalent
functionality. If this site were connected back to the head office, or to another
site that has a CallManager, then this CallManager can be eliminated, further
reducing costs. But, if this site must have dialing capability regardless of connectivity
to other sites, then a CallManager at this location must exist.