VCS and MCU with SIP/H323 - interworking call

[rajesh.kumar]

Desgin is: VCS, MCU 4505 and ISDN GW 3241 connected to the same LAN

Considering MCU is configured with both SIP and H323

All the end points are registered with VCS.

There is a multiway (with MCU) conference with two SIP end points one H323 end point and one H323 through ISDN Gateway.

All the four video calls will terminate on MCU.

Question is : MCU is registered with VCS with both SIP and H323. In this scenario is there any interworking call at MCU?

Second question is : What is the role of VCS during the conference?

During the conference call, if VCS is disconnected form the network, is there any impact on conference call? 

Third question is, what are the ports needs to be open between VCS and endpoint incase firewall exisits inbetween?

like VCS--------FW----------Endpoint1

                      |

                    WAN

                       | 

                      FW-----------Endpoint-2

Rgds

Rajesh Kumar

[rajesh.kumar]

Dear Team

Any feddback on the querry.

Thanks

Rgds

Rajesh

[Patrick Pettit]

HI Rajesh - To answer some of your questions here:

Question is

: MCU is registered with VCS with both SIP and H323. In this scenario is there any interworking call at MCU?

This will depend on how the multiway search rules are configured on the VCS.  It also depends on what call protocol is used when calling out to the other endpoints when initiating multiway conference.  If the order is the same, the VCS will more likely keep the native protocol if possible towards MCU when creating the conference. 

Our lab is set for either SIP or H323 in any given time, but customers do have both enabled and works. 

Second question is : What is the role of VCS during the conference?

During the conference call, if VCS is disconnected form the network, is there any impact on conference call? 

VCS will route your signalling for this meeting.  If any call is interworking, then the VCS will route media in that case and media will funnel between VCS and the two endpoints its interworking.  If VCS were to lose power or shutdown for some reason, then more likely your calls will disconnect. 

Third question is, what are the ports needs to be open between VCS and endpoint incase firewall exisits inbetween?

like VCS--------FW----------Endpoint1

                      |

                    WAN

                       | 

                      FW-----------Endpoint-2

This is one is a bit more loaded, and it depends on what the VCS is doing.  If VCS is interworking then certain media ranges need to be open between endpoint 1 and 2.  If the call is not interworked, media will more likley go between endpoint 1 and 2.  Each media range and signalling range is different for the product:

MXP:

http://www.cisco.com/en/US/docs/telepresence/endpoint/articles_doc/telepresence_endpoints_knowledge_base_articles.pdf

602: Which IP ports are used by the H.323 and SIP protocol for the Cisco TelePresence

System MXP endpoints?

The following ports cover both MultiSite and H.239 (dual stream):

For H.323:

Gatekeeper Discovery (RAS) – Port 1719 – UDP

Q.931 call Setup – Port 1720 – TCP

H.245 – Port Range 5555-5574 – TCP

Video – Port Range 2326-2485 – UDP

Audio – Port Range 2326-2485 – UDP

Data/FECC – Port Range – 2326-2485 – UDP

For SIP:

SIP messages – Port 5060 – UDP/TCP

SIP messages – Port 5061 – TLS(TCP)

H.245 – Port Range 5555-5574 – TCP

Video – Port Range 2326-2485 – UDP

Audio – Port Range 2326-2485 – UDP

VCS port ranges can be found in Admin Guide:

http://www.cisco.com/en/US/docs/telepresence/infrastructure/vcs/admin_guide/Cisco_VCS_Administrator_Guide_X7-1.pdf

Hope this helps. 

VR

Patrick

[rajesh.kumar]

Dear Patrick

Thanks a lot.

Pls. clarify me, below two points.

1.If it is not interworking call. During conference call if VCS is out of network. Will it impact on ongoing conf. call?

2.How to I configure secure call (AES) between two end points (between two C20) which is registered with VCS?

Is it configuration will be done by administtrator or end user will have option to choose whether select AES secure call on per call basis?

Thds

Rajesh Kumar

[Patrick Pettit · Accepted solution]

Hi Rajesh,

1.If it is not interworking call. During conference call if VCS is out of network. Will it impact on ongoing conf. call?

-Yes.  Signalling routing through VCS and not media, so if signalling is lost, either side will disconnect the call. 

2.How to I configure secure call (AES) between two end points (between two C20) which is registered with VCS?

-Depends on SW packages etc.  VCS must have encryption SW package.  You will see this under Maint>Options under Active options on VCS.  Then each endpoint will need to support it as well.  if your running TCNC code, this is the non-encrypted code, then this won't have encryption.  If your running TC code, under the conference configuration on C20:

xConfiguration Conference [1..1] Encryption Mode:

You have Off, On, or Best Effort.  If set to Best Effort, would negotiate encryption or not based on far side capabilities.  If the far end doesn't support it, it will still connect without encryption.  If set to ON, the call will fail cause encryption is not supported on the other side.  Best to set to Best Effort and see where that leads you and see if you get the desired affect in what your looking at doing. 

Hope this helps. 

VR

Patrick