250 sessions limit when using LGW with Wx Contact Centre

[mrvoipstuff]

newbie to WxCC ... trying to understand the 250 sessions max. limit as we are planning to use LGW with Wx Contact centre. Below is pretty much how our setup would be like .. CUBE will be using standard internet connection behind NAT.  

Now for an active agent call - I understand there will be 1 session active between CUBE to Wx CC and another session from Wx CC to the agent....I've bundled them together (2 and 3) in the picture below .. from Wx CC perspective is it considered 1 session out of the 250 limit ? or is it 2 sessions out of the 250 limit ? I understand there are two separate sessions here but trying to understand from WxCC perspective when it takes the 250 limit into account.

Note there will be 2 CUBEs (1 in each DC) so all too possible for 1st session (PSTN => CUBE => WxCC) to be on one CUBE and other session (WxCC => CUBE ==> Agent MS Teams) to be on the 2nd CUBE ... btw just realizing as I'm typing whose holding the session together if both sessions are on different CUBEs ? CUBE2 has no means of knowing CUBE1 has an active session for that same call. thanks. 

[b.winter · Accepted solution]

Hi again,

My opinion is, that 1 "complete" call (1 inbound to WxCC and 1 outbound to the agent) counts as 2 sessions.
So if the limit is 250 sessions, you could have 125 "complete" calls.
The reason is, that the media will always be hairpinned in WxCC => the inbound session and the outbound session will never be tied together, like in a normal SIP dialog => therefore both call legs are separate sessions.

To your last paragraph:
It doesn't matter, if both CUBEs see each other or not, because as written above, both call legs are completely independent of each other. If the inbound call to WxCC is routed via CUBE 1, the call can be routed out from WxCC via CUBE 2 and vice-versa.

"whose holding the session together if both sessions are on different CUBEs ?" => WxCC, as it always hairpins the call => there will always be the loop which you have drawn: 1 --> 2 --> 3 --> 4

[mrvoipstuff]

thanks again for your reply   

That's what I thought would be the case so it's not quite 250 then. If all my advertised numbers were part of a single DID range then no problem I would've ported that range over to the Cisco cloud PSTN to get around the 250 limit as it's only associated with LGW. But for us every single DID range has one advertised number which means all those ranges would have to terminate on LGW first before reaching WxCC. The other numbers in that range are their MS Teams extensions which we are using direct routing on that CUBE to route to MS so range has to terminate on CUBE (LGW). 

Ok - What if I get the agents to use the Webex app so it's using an extension from within Wxcalling. In that case I presume it will just be the one call/session for an active agent call. As traffic would stay local within the WxCloud and no call out to CUBE. Would that understanding be correct? 

[b.winter]

I wouldn't say, the limit is on the customer side (on your side) / the CUBE, but it's a limit of the WxCC side.
I could imagine that this number comes from Cisco, because they restrict the max. sessions for each customer to the WxCC plattform / the WxCC SBCs.
So, for me it's not a restriction of the CUBE => CUBE supports up to the max. amount of calls the HW supports
"Local Gateway" is just a name and the function ist still just a SIP Trunk.

So, if your total number of simultaneous IVR calls + agent calls is higher than 250, then LGW on CUBE is not option.

[Shalid Kurunnan Chalil]

Hi,

This may not directly address your initial query, but if the 250-session limitation is a concern in the setup, you have the option to opt for the certificate-based local gateway, which supports more than 250 calls, extending up to 2000 sessions per CUBE.

Regards,

Disclaimer:

Responses are based on personal knowledge and experience. Consider them as guidance. Other members may offer different perspectives or better approaches. No responsibility is assumed for outcomes; discretion is advised.

[Elliot Dierksen]

I attended a session about this at CLUS last year. The session limit without certificate based had some to do with single control channel where certificate based had multiple control channels. Is that correct?

[b.winter]

Good point.

[mrvoipstuff]

interesting .. I will explore that option further. Up until now I was using registration based trunk to peer CUBE with WxCalling. Thanks ! 

[b.winter]

On the other hand, if you don't use Wx Calling, just WxCC, there is an option to connect the CUBE to something called "vPOP" bridge, which is not the same as LGW to Wx Calling.
And there, IIRC, is no limitation of amount of calls. Just how much your internet connection and the CUBE supports. But this should be discussed in the A2Q, and Cisco should give you that information.

Connection to the vPOP-Bridge is just a static SIP trunk between your CUBE and Cisco's CUBEs.
There are several possible connection types:

Your question about LGW refers to point 5.
vPOP-Bridge with BYO PSTN (CUBE) is point 3.

So if you just have WxCC on the Cisco Cloud, and everything else is non-Cisco-Cloud, I would say, option 3 with connection to the vPOP bridge is the better option.
I have built this scenario already for a few customers, because the endpoints are still on CUCM. In your case, it would be MS teams.

[mrvoipstuff]

yes vPOP could be another alternative option -  good to know. I had a read about it in the onboarding guide for WxCC.

not sure if my customer will be willing to consider given $ cost but anyway it could be an option. thanks. 

[Shalid Kurunnan Chalil]

You may find this Webex help article helpful to know more about it.  

 Configure Registration based Trunk  

Get-started-with-Local-Gateway 

@Elliot Dierksen Yeah, I attended a similar session, and they did mention something along those lines. Unfortunately, I don't recall the details exactly. I've checked my notes, but I couldn't find anything useful, except for the screenshot below that I took during the session. Even though it is not directly related, it might provide an overview of both methods.

Regards,

[mrvoipstuff]

that's excellent info on the link. thanks. looks like cert based registration will do.

[b.winter]

https://help.webex.com/en-us/article/t9xctu/Get-started-with-Local-Gateway#local-gateway-trunking-models

[mrvoipstuff]

couldn't find any reference to it. only thing i could find is below where it says LGW regardless of platform (doesn't mention registration method) 

https://community.cisco.com/t5/contact-center/250-sessions-limit-when-using-lgw-with-wx-contact-centre/m-p/5003198#M128749 (p. 16)