Information Technology Reference
In-Depth Information
9.
To p r o v e t h a t c a l l s c a n r u n o v e r t h e WA N l i n k s , i m p l e m e n t a p i l o t s i t e . T h e p i l o t
would test the design's functionality over the WAN with or without FTP traffic.
10.
Recommend the use of Survivable Remote Site Telephony (SRST) to provide voice
services in the event of WAN failure, and reroute calls to the (PSTN).
11.
Figure 16-4 shows the diagram, which shows headquarters and two remote sites for
clarity. This architecture is duplicated for all remote sites. Each site uses a voice router
that is connected to both the IP WAN and the PSTN. SRST provides voice survivabil-
ity in the case of WAN failure. A CM cluster is implemented at the headquarters. The
Cisco Unified Communications Manager (CUCM) servers are in the data center in a
redundant network.
Centralized
CallManager Cluster
IP WAN
Router/GW
PSTN
DSP
V
V
IP WAN
Router/GW
SRST
Remote
Sites
Headquarters
IP WAN
V
IP WAN
Router/GW
SRST
Figure 16-4
Headquarters and Two Remote Sites
Beauty Things is a chain of stores that sell beauty supplies. Its headquarters is in Houston,
Te x a s , a n d m o r e t h a n 6 0 s t o r e s a r e l o c a t e d t h r o u g h o u t t h e U n i t e d S t a t e s . T h e C I O t e l l s
you that they are in the middle of a WAN migration from Frame Relay to MPLS. It will be
completed in two months. Most WAN links are less than 384 kbps.
After the WAN migration is complete, the CIO wants to use VoIP for voice calls between
stores. Most of the traffic is from remote stores to the HQ locations. He wants to com-
plete the VoIP project within the next six months and within the established budget. Each
store will have five concurrent calls back to headquarters.
is assigned the differentiated services code point (DSCP) listed in Table 16-4.
