Seems like lately there’s been some operators that have expressed frustration due to frequent issues with ePMP. I thought I’d share some of the tips and tricks that I’ve learned over the years since first deploying ePMP back when it was first released by Cambium. We have a mixture of e1k, e2k, e3k… over 30 AP’s and over 300 clients. My operating philosophy is to have the radios do as little as possible, disabling anything that isn’t specifically being used, and allowing them to focus on just shuffling packets back and forth across interfaces.
Here are my practices that keep ePMP running smoothly:
1. Use the newest firmware on everything, do not revert. I religiously update to every new release. ATM we use 4.5.6 on everything (e1k, e2k, e3k). The reason why you want to use the newest firmware is that if you do have issues, it needs to be fixed and patched going forward. Only roll back to an older firmware if advised to by Cambium and you have an open ticket.
2. For those sites which you need GPS synchronization, have a backup, like Packetflux. Almost all of our sites have some form of Packetflux sync injection. We also use external puck antennas on all of our ePMP radios. With this combo you will never lose sync again.
3. We try to keep things as simple as possible for the radios. This means, no VLAN’s, no PPPoE, no RADIUS, no LLDP, no multicast, no firewall or filtering rules on the AP or SM’s, no broadcast/multicast shaping, no other services that aren’t specifically needed.
On the AP we enable QoS and define some MIR’s, enable cnMaestro, enable SM isolation, NTP, syslog, SNMP, and WPA2 security, ethernet MTU 1700, disable system and agent logs.
On the SM we enable NAT, QoS, Traffic and VoIP priority enabled, SNMP, ethernet MTU 1700, uPNP & NAT-PMP enabled, and all the “Advanced” options disabled EXCEPT for NAT helper for sip (enabled), disable system and agent logs, and of course we enable cnMaestro.
Disable any ports not in use, like unused SFP, or AUX ports on all radios.
4. The powers that be at Cambium will probably get grumpy with me about this, but I would avoid using ePMP or PTP550 for PtP’s on larger networks, especially ones that aren’t L3 routed and using something like OSPF. I only use 5GHz PtP’s for small, end of the line stubs on the network behind a router, where there’s no strange/spurious broadcast traffic to touch them. I’ve had frequent issues with ePMP and PTP550 and even PTP670 when I try to use them to link larger sites… strange issues where mgmt interface disappear, ethernet ports locking up, strange stuff like that, so I just avoid it from now on. I now use licensed links, like PTP820 or AF11’s right out of the gate now.
I think that’s about it, if I remember anything else I’ll update this.
Do you have a large ePMP network? Do you employ any of the above mentioned suggestions? What are some of the tips and tricks that you use to make sure things run smoothly?