Out of curiosity, I decided to do a little research on competing technologies.
According to Yahoo Finance: Nortel Networks, Avaya, and Juniper are direct market competitors with Cisco. Below is a rough comparison of the companies.
http://finance.yahoo.com/q/co?s=CSCO
Cisco Juniper Nortel Avaya
Market capital 122bil 9bil 9bil 5bil (respectively)
Then, I checked out certification programs for each.
Avaya's website was a bit hard to navigate; it seems that they have one certificatioin track that goes from beginner, intermediate, to expert. There are no other options. It looks that Avaya does primarily IP telephony. Though, this is by no means official reporting because I didn't spend that much time on the site.
Nortel Networks has a variety of certifications that mostly go from a beginner to professional level. There's an "expert" certification in the works.
Juniper certification process is very similar to Cisco. The "expert" cert includes an 8 hour hands-on lab test just like Cisco's does. There don't seem to be any different varieties of the expert level though.
Diagnosis? I dunno, but, I can say with some confidence that there don't seem to be many training sites that even acknowledge certs from these other vendors.
Does anyone have any input?