addresses (packets are like a letter sent to a friend who then puts the received envelope in another envelope and sends it to you). The node may also do error detection and or correction and other processing. The node may also have to generate a log message for every packet it handles. It may have to wait till the log buffer has loaded a previous log entry to the log database before generating the next log message. The semiconductors that support this processing may be very fast. Still, it takes time—and that time compounds with the number of nodes that have to be traversed. Modern networks have a very large number of nodes.

Circuit switching and latency

In a circuit-switched network, intermediate nodes do not have to do this kind of processing. Instead, at the beginning of the communication session, there is call setup processing. Call setup involves a set of messages and responses to those messages that tell intermediate nodes how to arrange themselves to allow data to pass to its intended destination. Call setup takes time—but, once call setup is done, there is little or no processing delay in the network. Thus, circuit switching is transmission efficient when communications sessions are long in duration and volume-heavy.

Virtual circuit-switched networks

Virtual circuit-switched networks were developed and widely used in the early days of packet switching to ease the transition and in the middle years to improve efficiency. Those mechanisms developed in the middle years are contained as legacy capabilities in many nodes today. When activated, they examine flows of packets. When they find that a high level of traffic entering one node is always bound for the same second node, the system stops looking at addresses and forwards all packets to that second node.

The metaverse and latency

As we can see in the HSBG example, metaverse interactions are likely to have the key characteristics that make it hard for packet switching and easy for circuit switching. The added latency created by all the internode processing in a packet network adds significant latency to the nonreducible latency from propagation delay. Because once started, metaverse interactions are likely to continue for some time, they are not so concerned by call setup latency. Also, once set up, they are likely to have significant volume—thus, reducing concerns about fill efficiency.

Likely outcomes

We are already seeing the beginnings of a search for alternative networking approaches. Many people working on 6G cellular are working on alternatives to TCP/IP. We are likely to see similar efforts in the fiber and other terrestrial network technologies. These are likely to have a foundation drawing heavily on circuit-switched concepts. But these new standards and associated products will take some time to get to large installed bases.

As metaverse applications take off, CSPs and cloud providers are likely to face demands for low latency from existing infrastructure. One way to fill the gap before new technology solutions appear is to dust off the expertise in and software support for virtual packet switching. Making the existing installed base perform with lower latencies while onboarding new technologies will require very good intersystem cooperation between all the components in large networks. Large networks are going to become more complex and volatile. The only way to achieve that kind of intersystem cooperation is with fine-grained orchestration. Quickly developing and fielding this fine-grained orchestration is critical. CSPs, cloud providers, and the vendors supporting them should be preparing for this now.

Note: the author was a very early and strong proponent of packet-switching. He contributed to the first packet-switching standard (X.25) and designed the first international packet-switching network.  He continues to work on standards for, and designs of, semiconductors and software for LANs, WLANs, WiFi, and cellular using packet switching as appropriate. He sees the evolution of technology as having pushed many portions of our information technology space to and beyond the edges of what packet-switching technology can deliver.