NETW250 Week 1 iLab – How Is the PSTN Used Today?
What is a VPN as you understand it (before reading AT&T’s description)? (5 points)
What is a VPN as AT&T describes it? (5 points)
What is the difference between a MPLS and an IPSec VPN as AT&T explains it? (5 points)
What is metro Ethernet? (5 points)
What are SONET ring services? (5 points)
Does AT&T offer frame relay? (5 points)
Does AT&T offer T-carrier service, also called private line? (5 points)
AT&T offers DWDM as a service. What is DWDM? (5 points)
NETW250 Week 2 iLab: Avaya IP Office Phone System
NETW250 Week 3 iLab: Observing VoIP Protocols Using Wireshark
NETW250 Week 4 iLab: Unified Communications Server Elastix: A One-Server Scenario
NETW250 Week 5iLab: VoIP Traffic Engineering
Task 1—Calculate the VoIP traffic load in access trunks to the Internet.
Q1. What is the number of call-attempts during the busy hour at the company’s location?
Q2. What is the traffic load in Erlangs during the busy hour? Show calculation and units.
Q3. What in the dimension of traffic measurement unit Erlang?
Task 2—Calculate the number of SIP trunks and access link bandwidth required for VoIP calls to the Internet.
Q4. What is the difference between a completed call and a callattempt?
Q5. What is the number of SIP trunks (lines from the online calculator) required to meet company’s need?
Q6. What access bandwidth (Kbps from the online calculator) is required to connect the company’s location to the Internet?
Q7. If T1 bandwidth is 1.544 Mbps, T3 bandwidth is 44.736 Mbps, and there are 28 T1 in a T3, what access connection(s) does the company need to lease in terms of T1 and/or T3? Show the calculation.
Q8. Enter a screenshot below showing the results from the Erlang-to-VoIP bandwidth calculator.
Task 3—Calculate the number of backup access channels to the PSTN.
Q9. How many analog lines does the company need to subscribe from a TSP? Include a screenshot below that shows the calculator results. 48
Q10. Assume that each analog line can carry 1 Erlang of voice traffic. What is the utilization of the PSTN trunks if an Internet failure occurs during busy hour? Show the calculation.?
NETW250 Week 6iLab: Troubleshooting VoIP Traffic
Examining VoIP Call Streams
Answer the following questions based on the iLab6-Capture1.pcap file.
Which protocol was used for the telephone to attempt to register with the PBX?
What is the type or name of the message or request that is sent by the telephone to the PBX?
The TCP or UDP port that a VoIP protocol uses must be kept open in a firewall so that the traffic can pass through. In this same file, what TCP or UDP port is used in Frame 1?
The exchange between the telephone and PBX specifics a realm they belong to. What is the name of this realm?
Answer the following questions based on the iLab6-Capture3 file.
In the file, SIP creates a connection between the two telephones and RTP carries the call session itself. How many frames are required by SIP to just setup this call?
In the file, SIP creates a link between the two telephones and RTP carries the call itself. How many frames are required by SIP to just end the call?
Answer the following question based on the iLab6-Capture4.pcap file.
The RTP protocol is defined in an IETF RFC document; it specifies how RTP operates. What is this RFC?
Answer the following questions based on the iLab6-Capture7 file.
The RTCP protocol appears in frame 529. What does RTCP stand for?
In the capture file, the RTCP protocol appears several times. What is the function of RTCP?
In the capture file, another protocol appears occasionally with SIP. The frames show it as SIP/SDP. What does SDP stand for?
NETW250 Week 7 iLab: Unified Communications Server Elastix:A Two-Server Scenario
Exercise 1—Testing phone calls between extensions before the interexchange trunk configuration
Exercise 2—Configuring interexchange trunks and routes on two Elastix servers
Task 3—Take two screenshots showing the configuration parameters of newly created trunk ELASTIX2.The screenshots should show the same information included in Figure 11 and Figure12
Task 4—Takea screenshot showing that route Elastix2Exts is added to the ELASTIX_SRV1 server as demonstrated in Figure 18
Task 5—Takea screenshot showing the configuration parameters of route Elastix2Exts on server ELASTIX_SRV1 as demonstrated in Figure 17.
Task 6—Take a screenshot of the configuraion page showing that trunk ELASTIX1(iax) is created on ELASTIX_SRV2 as demontratedin Figure 19.
Task 7—Take two screenshots showing the configuration parameters of newly created trunk ELASTIX1on server ELASTIX_SRV1.The screenshots should show the same information included in Figure 20 and Figure 21
8—Takea screenshot showing that route Elastix1Exts is added tothe ELASTIX_SRV2 server as demonstrated in Figure 22.
Task 9—Takea screenshot showing the configuration parameters of route Elastix1Exts on server ELASTIX_SRV2 as demonstrated in Figure 23.
Task 10—Question:Compare and contrast SIP and IAX trunks, including typical applications where they are used and standards they based on. Cite references and sources used in this research.
Exercise 3—Testing phone calls between interexchange extensions after the trunk configuration
Task 11—Take a screenshot of softphones 101 and 204 showing the call iscoming through as demonstrated in Figure 24.
Task 12—Take a screenshot of softphones 102 and 203 showing the call iscoming through as demonstrated in Figure 25.