[VoiceOps] SIP trunk providers emitting RTP packets containing wrong number of samples

[Liudvikas Bukys]

My company (a SIP equipment manufacturer) has noticed a sudden flurry of
problems related to RTP streams containing some packets with the wrong
number of samples (different from what was negotiated).  Our equipment
negotiates 20ms packets, we're seeing the emission of a few 5ms packets
with MARK bit set, before the 20ms packets start flowing.    I theorized
that some vendor's SBC or Media Gateway has released software that causes
this.

It has erupted at multiple customers.  I thought there was no commonality
of carrier or trunk provider, but today I heard a report that T-Mobile is
definitely implicated and reproducible.  Other sources are possible too.

Has anyone else noticed this?

Does anyone have a good contact for SIP-related matters at T-Mobile?
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