This optional parameter allows you to define the Supported
Vendor Ids announced in CER. There is no default and no
Supported-Vendor-Id is announced by default. Keyword "DictVendors" is an
alias group for all vendors in the default dictionary and the dictionary
file configured with DiameterDictionaryFile.
# Tell the peer we support all the vendors in our
# default and DiameterDictionaryFile dictionaries
SupportedVendorIds DictVendors