Dual Homing and Split Core

[MagnaRGP]

Good Day all.

I have a couple of questions regarding Dual Homing and Split Cores.

1. When do MGCs switch from one port to the other? When they sense that traffic is failing to get through or only when a switch dies/port is disconnected. I ask because I recently had a scenario where a TLAN switch uplink port died, but the physical port the MGC was connected to was fine. If this MGC was dual homed, would it have switched to the other port in this scenario?
2. I have been shown some cuts from an Nortel doc which shows the HSP port on a CPPM-CS being looped into the CT port on an MGC for the purpose of redundancy of the HSP link. I didn't think this was possible. Is it?
3. Is there any programming required to enable the dual homing feature, or simply plug in the ports?

Thanks.

 

[MagnaRGP]

I suppose that I should add CS1000E HA rel 5.5

 

[allenmac]

Everything I read in the NTP's points to the MGC's supporting dual homing, not the call servers.

My understanding of the answers to your questions follows:

1. When an MGC loses connection to the active call server, the first thing it tries is to re-establish connection on the dual-homed port. If that fails, it will try to conntect to an alternate call server if available. Connectivity to the call server dictates when the dual homed ports switch.

2. Every piece of documentation I have seen shows the HSP connection as point to point, and not dual homing. The CT port on the MGC card is dedicated to the CPPM signaling server, and provides T-LAN connectivity only. The CE port on the MGC card is dedicated to CPPM connectivity (either CS or SS), and provides E-LAN connectivity only.

3. I have not come across any specific configuration tasks in the NTP's, so I don't believe there is anything special you need to do on the CS1000 side (I could be wrong), I do not know if anything needs to be configured in the network gear to support this.

 

[MagnaRGP]

Just thought I'd confirm something about my question 2. You CAN dual home the HSP port. You can loop it through the CT port on an MGC. You cannot, however have any DSP's on that MGC, so it basically becomes a really expensive switch. This of course presumes that you have the TLAN ports connected to the network on the correct VLANs.

 

[allenmac]

Thanks for the info on dual homing the HSP. That's a nice little tidbit to keep in mind.