These came from Sipura, which Linksys bought. The last time I had some in service, they were responsible for connecting landlines for FAX and 911 service. (Thi

These came from Sipura, which Linksys bought. The last time I had some in service, they were responsible for connecting landlines for FAX and 911 service. (This was before VOIP exchanges had E911 availability and while FAX was still a viable protocol for signed documents.)