STP and VoIP system

[dambar_nai]

Hello all,

First of all, I'd like to say that I am very new to the community so your patience is highly appreciated. I apologize if I placed my questions in the wrong place.
I am also not a network engineer so thank you in advance for understanding if I ask dumb questions.

We have a Mitel VoIP system that was recently upgraded from a Shoretel 14.2 to Mitel Connect.
After the upgrade, we started experiencing some issues which Mitel blames on our network.
They insist that STP must be turned off on all the ports that have any VoIP phone and switch connected to which will create a problem since most ports the IP phones are connected to are hybrid ports for both voice and data VLANs since they are also shared with workstations.

Here's some information about the switches:
There are 14 different offices that each have an HP 1910 as a core switch except for two major sites that have HP 2920. Depending on the site's size, there are also HP 1910 switches used as access switches, except two that have only a core switch.
So my questions are, how is it possible to disable STP if at all in this case scenario? Is there a case scenario where I can disable it on the access switches ports but keep it enabled on the core switches?
Also, the HP 1910 switches are configured with STP mode RSTP. The 2920s on the other hand are configured with MSTP mode. The other option is RPVST. So my questions are, can that cause any issues? Also, what is the difference between RSTP and RPVST? Can I assume that they serve the same purpose in my case scenario so that there is no risk in changing it from MSTP to RPVST?

Thanks!

[akg7]

Hello,

RSTP:
Based on the IEEE 802.1w standard, Rapid Spanning Tree Protocol (RSTP) is an optimized version of the
IEEE 802.1D standard, Spanning Tree Protocol (STP). It achieves rapid network convergence by allowing
a newly elected root port or designated port to enter the forwarding state much quicker under certain
conditions than STP. Although RSTP supports rapid network convergence.

MSTP:
Developed based on the IEEE 802.1s standard, Multiple Spanning Tree Protocol (MSTP) overcomes the
limitations of STP and RSTP. In addition to support for rapid network convergence, it allows data flows
of different VLANs to be forwarded along separate paths, providing a better load-sharing mechanism
for redundant links.
MSTP uses multiple spanning tree instances with separate forwarding topologies. Each instance is
composed of one or more VLANs, which significantly improves network link utilization and the speed of
reconvergence after a failure in the network’s physical topology.

RPVST:
Cisco implements Per-VLAN Spanning Tree Plus (PVST+), which is based on the IEEE 802.1D standard
(Spanning Tree Protocol [STP]) and additional proprietary extensions, or Rapid Per-VLAN Spanning Tree
Plus (RPVST+), which is based on the IEEE 802.1w standard (Rapid STP [RSTP]) and additional
proprietary extensions.

Aruba ProVision supports RSTP, but Multiple STP (MSTP) is the default STP version. MSTP is not
enabled by default. When MSTP is enabled, all ports are auto-edge-ports.

Comware7 supports RSTP, but MSTP is the default STP version. MSTP is enabled by default.
When MSTP is enabled, all ports are non-edge ports.

By default MSTP is the default version in Aruba/Comware switches.

It is possible that you can disable the STP into access switch and it will remain in core switch.

If you want to disable STP globally into 1910 switch then you can go to Network > MSTP and select Disable into 'Enable STP Globally'
And to disable Port wise then go to Network > MSTP and click 'Port Setup' tab. Select port and disable port wise.
Make sure core switch is the root port. Root port might receive topology change notifications but it wont impact the network unless until loop is not there.

Refer below link for user guide and refer pg. 173.

https://support.hpe.com/hpesc/public/docDisplay?docId=c03941555

Thanks!

[Ivan_B]

Hello @dambar_nai !

They insist that STP must be turned off on all the ports that have any VoIP phone and switch connected to which will create a problem since most ports the IP phones are connected to are hybrid ports for both voice and data VLANs since they are also shared with workstations.

TBH before disabling something you need to be sure STP is the cause. There is nothing wrong in disabling STP if you are totally aware about all consequences for your network from stability point of view. With STP disabled any wrongly connected cable on the end user side may bring your whole network to a non-working or barely working state. I would suggest you to keep STP enabled and to configure all the switch ports that face workstations and/or phones as 'STP edge' ports. Lack of this configuration is the most frequently root cause for traffic forwarding interruptions in networks that use MSTP or RSTP. So, keep STP enabled on all switches, keep all switch-to-switch links as normal STP ports and configure ALL host (PC or phones) facing ports as STP edge ports.

Only after you implement this configuration you can evaluate if STP is a real issue for Mitel devices or it is really not and the issue was caused by a misconfigured STP environment.