Cisco TelePresence ISDN MSE 8321 redundancy discussion

[Arbenjamin]

Dear all,

The existing ISDN Gateway redundancy relies on the single hardware with multiple ports. So, there are two ISP directory numbers (each directory number comes with two cables).

However, our client would like have to better redundancy on the ISDN hardware. So, we would like to discuss on ISDN gateway hardware redundancy.  

Anyone knows about the cluster on ISDN gateway? Since I can't find any guideline on related tropic in the administrator guideline.

Best Regards

Ben Lai

[Lawrence James]

You can have some redundancy by assigning the same prefix to multiple gateways. Calls to this prefix will be serviced by the availible gateway.

What does the rest of the infrastructure look like?

Gatekeepers or VCS

MSE Chassis

MCU

TMS

Endpoints

Dial Plan - Does that gateway have to handle handle inbound calls as well with redundancy?

[Arbenjamin]

The rest of the infrastructure contain,

VCS 7.2 Cluster 

Two MSE chassis ( take consideration on redundancy )

MCU 4.4

Conductor

TMS 13.2

How I can achieve the same prefix to multiple gateway? Now, We are targeted on created two prefix to the two gateway.

Ideally, the two gateway should handle the inbound call with redundancy, however, we have no idea on this.

Best Regards,

Ben 

[Lawrence James · Accepted solution]

You would set this in the dial plan prefix field. Then each blade will register with the the VCS. Ensure that resource availability status is being sent to VCS as well.

Once done when a user dials the gateway prefix the VCS (ensure search rules are configured) will route the call to the available resource. You can do this with using different prefixes but it will require more complex configuration and setup. The built in Load Balancing feature in the blade only works on incoming calls.

Having different prefixes has the most benefit when the blades are located in different areas and you want to bypass toll charges or in multi tenant situation or other cases where use must be restricted/controlled.

So since you said you are leaning toward different prefixes the question is – what is the business case for this?

[Wayne DeNardi]

As ISDN is a legacy protocol (although, I agree it's still required in the current day) - it could be a better use of time and funds to migrate more to the IP world and away from ISDN as much as possible, reducing the need for ISDN, and therefore the need to have redundant equipment and services to deal with the legacy connectivity.

[Martin Koch]

I agree to 90% with wayne, but it might also be that he needs ISDN for plain telephony or

he has some contracts or dependencies so he can not get rid of it right now.

Redundancy on ISDN is nothing new. There are some ways using prefixes and/or CPLs.

for outbound calls.

For inbound calls you would need to check with the ISDN provider can support.