Describe some circumstances where it might be desirable to use source routing rather than let the routers make the routing decision

some have built technology like spoofed call blockers into their networks, so there's nothing you would even have to install.

this happens because the number is known for scamming, they don't want it to me known as "scam likely." perhaps it's just a telemarketer. maybe it's an identity thief. it might even be a scam artist.  

either way, "scam likely" is probably not an old friend whose number you forgot that you saved. it's your wireless carrier's way of letting you know: answer at your own risk.

explanation:

to combat the seemingly rising epidemic of spam callers in the u.s., the nation's four major wireless carriers have been trying out new methods to reduce the number of unsolicited calls americans receive each day.

some have built technology like spoofed call blockers into their networks, so there's nothing you would even have to install.

hope this . mark me brainliest.