单项选择题 Jitterisanunwantedvariationofoneormorecharacteristicsofaperiodicsignalinelectronicsand telecommunicationsand（）referstocallissuesthatcausevariationsintimingortimeofarrival.

单项选择题 WhichVPNmanagementfeaturewouldbeconsideredtoensurethatthenetworkhadtheleast disruptionofservicewhenmakingtopologychanges？（）

多项选择题 Which two of these are correct regarding the recommended practice for distribution layer designbased on the following configuration？（）