SBA deployment and testing with Lync 2013 Part II

In Part 1 of this article we walked through the steps to deploy a Lync 2013 SBA in a simulated branch office environment. Here in Part II, we will perform some tests of the SBA to verify the correct functional behavior using Microsoft-certified IP deskphones such as the Polycom CX600 LPE and the Polycom VVX310/410 Business Media phones. We also collect some performance results of the failover and failback times in this lab. The diagram for this lab environment consists of a Lync 2013 SE FE server in the "Main Site" and an Audiocodes M800 SBA in the "Branch Site". In the main site we have a Lync 2013 PC Client and a Polycom VVX410 phone and both accounts used to login are homed on the Lync SE FE server. At the branch site we have a Polycom CX600 phone and a Polycom VVX310 phone and both account used to login are homed on the SBA. Below is the diagram of this setup:

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The following tests will be performed in the sequence below:
Test #1: WAN Link Up: 
    1a. Login to all phones using PIN Auth
    1b. Login to all phones using NTLM Auth
    1c. P2P voice calls between Main site and Branch Site
    1d. Multiparty voice calls between Main site and Branch Site

Test #2: WAN Link Down
     2a. Phone registration status after WAN Link is down and failover time
     2b. Initiate P2P calls within Branch site
     2c. Phone registration status after WAN Link is restored and failback time


Test #3: WAN Link Down during active calls
     3a. Initiate P2P voice call within Branch site, then WAN Link fails
     3b. Initiate multiparty voice call between Main site and Branch site, then WAN Link fails

Test #1: WAN Link Up

1a. Login to all phones using PIN Auth
For this test we first remove any existing certificates on the phone. For the CX600 this done via factory reset and for the VVX310/410, we manually delete the existing CA certificate using the phone's UI. Below is the screen shot of the phones before login:

Login via PIN Auth on the CX600, VVX410 and VVX310 took approximately 14.45s, 36.79s and 16.66s respectively for the CX600, VVX410 and VVX310 respectively. Note that PIN Auth would not have worked if the WAN Link was down as explained in Jeff's Schertz article. Below is the screen capture of the 3 phones signed in via PIN Auth:

1b. Login to all phones using NTLM Auth
Next we sign out from all phones and re-login using NTLM Auth. On the CX600 this is done via USB tethering and signing in using a Lync client on a PC. On the VVX310/410, login via NTLM can be done directly on the phone UI itself. Login via NTLM took approximately 20.21s, 9.40s and 6.53s for the CX600, VVX410 and VVX310 respectively. Below are the screen shots of the phones after login:

1c. P2P voice calls between Main site and Branch Site
We initiate a call between the VVX410 which is homed on Main site and the VVX310 which is homed on Branch site. This works fine as expected.

1d. Multiparty voice calls between Main site and Branch Site
Using the Lync client on PC, we select all 3 phones and start a multiparty voice call. Below is the screen capture of the endpoints:

Test #2: WAN Link Down

2a. Phone registration status after WAN Link is down and failover time
Now we disconnect the cable between Switch A and Switch B thereby simulating a WAN down scenario. The phones that will be affected will be the CX600 and the VVX310 as these are devices homed on the branch site SBA. After disconnecting the cable, the 2 phones are placed into "Limited functionality due to outage" state in failover time of approx. 60 secs as shown below:

2b. Initiate P2P calls within Branch site
While in this state, these 2 phones in the branch site are still able to call each other. However, calls to main site will not work and presence states are no longer available

2c. Phone registration status after WAN Link is restored and failback time
At this stage of the tests, we proceed to re-connect the cable between Switch A and Switch B, thereby restoring the WAN Link. Within a failback time of approx. 1m 30 secs the 2 phones are restored back to normal status:

Test #3: WAN Link Down during active calls

3a. Initiate P2P voice call within Branch site, then WAN Link fails
As expected the voice call continues without any interruption even though the 2 phones are in "Limited functionality mode":

3b. Initiate multiparty voice call between Main site and Branch site, then WAN Link fails
In this final test scenario, we use the Lync client at the main site to initiate a multiparty voice conference with all 3 phones similar to what was done in test 1d. All 3 phones ring simultaneously and we answer the calls on each phone. While the conference is ongoing, we then disconnect the cable between Switch A and Switch B to simulate a WAN link down. Within approx 32 secs the call is dropped on the CX600 with a "Conference error" message. In addition, both CX600 and VVX310 are in limited functionality mode after approx. 60 secs. This is in line with expectations as the call is hosted on the AVMCU which resides in the main site SE FE server. Without the WAN link the multiparty call cannot continue.

Conclusion
As per test results, SBA functionality is pretty much the same in Lync 2013 as in Lync 2010. Failover and failback times are within the configured range which is default at 120 sec and 240 sec for this test environment. For reference, the firmware versions used in this test are 4.0.7577.4411 for the CX600 and 5.0.1.4068 for both the VVX310/410.