2, you would deploy
several large gateways to support the traffi c for each data center. Calls that are bound for the
outside are routed over the data center gateways and calls that are bound for internal users
are routed over the PSTN to the data center gateway. Call routing at the data center will
determine how to route calls to the targeted users.
178 Chapter 6 ??? Confi guring the Mediation Server
You can deploy gateways in a variety of ways, each with its advantages and disadvantages.
You need to consider the goals of your deployment when choosing your locations.
Sizing for the gateways can vary based on traffi c and location. You need to consider the
number of phone calls you can expect and the types of users in each location where you are
placing gateways. Microsoft offers the following guidelines:
?– A light telephone user (one PSTN call per hour) should allocate one port per 15 users.
?– A moderate telephone user (two or more PSTN calls per hour) should allocate one
port per 10 users.
?– A heavy telephone user (three or more PSTN calls per hour) should allocate one
port per fi ve users.
Figure 6.2 A Data Center Confi guration
Configuring the Mediation Server ??? Chapter 6 179
You have a choice of deploying fewer large gateways or more small gateways for any number
of users you have to support. It is a good idea to have at least two gateways to provide some
level of fault tolerance.
Each basic media gateway you deploy needs to have one Mediation Server.
Pages:
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229