Information Technology Reference
In-Depth Information
3.
What are the network's technical requirements?
4.
What are the network's technical constraints?
5.
Approximately how many IP phones should the network support?
6.
What type of UC architecture should you propose?
7.
What quality of service (QoS) features would you propose for the WAN?
8.
What PoE recommendations would you make?
9.
Wo u l d y o u p r o p o s e a p r o t o t y p e o r a p i l o t ?
10.
What solution do you suggest for voice redundancy at the remote sites?
11.
Diagram the proposed solution.
Scenario Two Answers
1.
The company wants to provide voice services in a converged network.
2.
The solution should provide reduced costs over the existing separate voice and
data networks.
3.
The technical requirements are as follows:
Provide UC over the data network.
Provide voice redundancy or failover for the remote sites.
Prevent FTP traffic from impacting the voice traffic.
4.
The technical constraint is as follows:
Call-processing servers need to be located at headquarters, and IP phones need to
continue to work even if the WAN goes down or has limited bandwidth.
5.
There are 200 IP phones at headquarters, and 35 * 30 = 1050 remote IP phones, for a
total of 1250 IP phones.
6.
Propose the WAN centralized call-processing architecture with a CallManager (CM)
cluster at headquarters.
7.
Use low-latency queuing (LLQ) on the WAN links to give the highest priority to voice
traffic. Then define traffic classes for regular traffic and FTP traffic. Make bandwidth
reservations for the voice traffic and maximum bandwidth restrictions for the FTP
traffic. Call Admission Control (CAC) is recommended to limit the number of calls
from and to a remote site. CAC should be used to reroute calls to the public switched
telephone network (PSTN) if there is no available bandwidth to support a new call.
For example, you c an limit c alls at sites w ith 384k links to only three c alls v ia the
WA N . A n y a d d i t i o n a l c a l l g e t s r o u t e d t o t h e P S T N .
8.
Recommend standard-based Power over Ethernet (PoE), also known as IEEE (802.3af)
for the s w itche s to prov ide power to the IP phone s.
