This so-called “vNext” release of Windows Server LTSC is available in “Desktop Experience and Server Core installation options for Datacenter and Standard editions,” the announcement indicated. The ISO can be had in 18 languages, but a Hyper-V virtual hard disk (VHDX) format is just available in English.
LTSC represents a Windows Server product that has Microsoft’s traditional five years of “mainstream” support plus five years of “extended” support, which follows Microsoft’s Fixed lifecycle product-support model. The current LTSC product is Windows Server 2019 version 1809, which is supported until Jan. 9, 2029, according to Microsoft’s “Windows Server Release Information” document.
Microsoft also offers a semiannual channel release version of Windows Server that’s supported for 18 months and follows Microsoft’s Modern lifecycle product-support model.
Microsoft described a bunch of somewhat esoteric-sounding features associated with this Windows Insider Program release of Windows Server vNext LTSC. However, some of them (listed below) seemed more down to earth.
Smaller Container Images
Server Core users of Windows Server vNext LTSC will be getting container images that are “20 percent smaller,” Microsoft’s announcement promised. The use of a .NET Framework image is recommended to get that kind of result, it added.
Packet Monitor TCP/IP Support
Packet Monitor (also known as “PacketMon”) gets TCP/IP transport security support in Windows Server vNext LTSC. This diagnostic tool is used for assessing network connectivity issues, including in virtualized environments. It can be used for “packet capture, packet drop detection, packet filtering and counting for virtualization scenarios, like container networking and SDN [software-defined networking],” the announcement explained.
A May Microsoft blog on Packet Monitor indicated that “PacketMon was first released in Windows 10 and Windows Server 2019 version 1809 (October 2018 update),” but it had a few limitations back then. PacketMon lacked firewall integration and only provided packet “drop reporting” for supported components. It just had support for “Ethernet media.”
Server Message Block AES-256 Encryption
Windows Server vNext LTSC has support for AES-256 encryption in Server Message Block (SMB). AES-256 has a key length of 256 bits and is currently considered to be unbreakable.
SMB in Windows Server vNext also uses compression to “improve network performance,” Microsoft indicated.
Windows Sever vNext also is getting MsQuic, Microsoft’s open source library for implementing the budding QUIC transport protocol. The QUIC protocol is also referred to as “HTTP/3.”
Microsoft is previewing MsQuic in Microsoft 365, .NET Core 5.0, as well as Server Message Block (SMB) in Windows Server. Microsoft had explained back in March that SMB over QUIC can serve as a virtual private network replacement that’s always encrypted, replacing the TCP/IP and Remote Direct Memory Access protocols. It can help prevent spoofing and man-in-the-middle attacks.
Google originally developed QUIC and has its own “gQUIC” implementation, but QUIC is now a project maintained by the Internet Engineering Task Force with the aim of creating a worldwide standard.
QUIC is built on top of the User Datagram Protocol (UDP) protocol for streaming data, and Microsoft’s announcement claimed that Windows Server vNext will make UDP perform “to a level on par with TCP” via UDP Segmentation Offload (USO) technology. USO uses a system’s network interface cards to offload datagrams (that is, IP packets) that “are larger than the maximum transmission unit,” reducing CPU use compared with TCP/IP processing.
“USO moves most of the work required to send UDP packets from the CPU to the NIC’s specialized hardware,” the announcement explained. Additionally, Microsoft claims a UDP Receive Side Coalescing technology in Windows Server vNext will serve to reduce CPU usage with UDP traffic.
BitLocker Keys Storage
Another notable item is Windows Server vNext LTSC is the ability to store BitLocker keys locally in failover clusters in an encrypted form. It’s a security measure that avoids the present scenario of having the BitLocker key be dependent on the Cluster Name Object, which requires using Active Directory. Apparently, there will be less of dependency on using Active Directory with this key storage approach.
Many more capabilities in Windows Server vNext can be found in Microsoft’s announcement.