Voice quality degradation of VoIP calls noticed after replacement legacy ERS with ERS3600
After replacement legacy, ERS 4500 with ERS 3600, a few seconds VoIP call interruption was noticed. Following symptoms were noticed:
Not all calls were affected
The problem was random
No lines congestion
No drops/errors were noticed on the path
Ethernet Routing Switch 3000 series
Any supported software version
The issue was due to bad configuration of the Rate Limit feature ported from legacy ERS4500. The ERS3000 series support packet per second [pps] only, as a rate-limit unit. Below is the representation of rate-limit options on ERS 3600:
ERS3600(config-if)#rate-limit both ?
Disabling rate limiting by the negation of rate limit command solved the problem:
ERS3600(config)#no rate-limit unit 1
It is highly recommended to review switch configuration and check for supported features, every time you are migrating from one platform to the other.