The value of tmnxOamTrCtlMaxTtl specifies the maximum time-to-live
value. This parameter is optional.
When tmnxOamTrCtlMaxTtl is not explicitly specified, the agent
defaults the value based on the 'tmnxOamTrCtlTestMode'.
In the case of 'lspTraceRoute' the default is set to 30.
In the case of 'icmpTraceRoute' the default is set to 30.
In the case of 'ldpTreeTrace' the default is set to 30.
In the case of 'vccvTraceRoute' the default is set to 8.
In the case of 'p2mplspTrace' the default is set to 30.
In the case of 'ethCfmLinkTrace' the default is set to 64.
Otherwise the default is set to 4.