Characters can upgrade cyberware or bioware systems in-place, eg. from Wired Reflexes 1 to 2, by paying the difference between the ratings (in nuyen and Essence.)
Removing augmentations leaves an “Essence hole”. Your Essence doesn’t go back up, but you can now get further augmentations installed without reducing your Essence further until the “hole” is filled.
The following items of cyberware include all the functionality of a datajack, including giving the user DNI and a port for direct wired connections:
All basic cyberware comes with a constantly running wireless Matrix connection. This applies even for ‘ware like cyberlimbs, where all the control the user needs is done via a direct neural shunt, so the wireless connection isn’t needed to use it directly.
This wireless connection is used for downloading firmware updates, running diagnostic routines, and communicating status and error reports back to the user (it’s hard for a cyberarm to tell its user its time for a maintenance routine without this connection. Although some corps have experimented with persistent itching sensations in particular spots, but it has not been popular.)
Where a piece of cyberware has no listed wireless/DNI bonus, a character can disable this wireless connection without penalty. This offers protection against interference from hostile deckers. However, it might attract attention from the authorities if the cyberware is visible but not wirelessly active, as that raises questions.
Corps do not encourage this behaviour in their own security personnel, as they prefer to keep a close eye on their wageslaves - especially the ones with guns, as wireless PANs and friend-or-foe tagging is key in preventing friendly fire incidents when the undertrained and underpaid guards get trigger-happy. Only the most elite troops, above HTR grade, are likely to engage in combat with wireless disabled.
The internal router is the device for streetsams who want to make themselves hacking-resilient without relying on a decker. It replaces the use of ubiquituous wireless connections to link together all your equipment with alternatives wherever possible. Internal cyberware systems are linked via subcutaneous wiring. Induction pads in the users palms are used to communicate with smartguns. Several discreet additional datajacks are included at the wrists, ankles, and base of the spine, for more convenient connection of wired gear.
The internal router also includes processing systems to mediate between otherwise-incompatible cyberware from different manufacturers.
In game terms, the user can benefit from all the usual bonuses for DNI without having to have most devices exposed to wireless hacking via the Matrix. An internal router system includes a datajack for “free”.
Grey/used/basic grade internal routers are extremely obvious to anyone looking at you, as they use visible subcutaneous wiring over large portions of your upper body, including the face and hands. This wiring becomes less visible in alpha and betaware, and is almost undetectable in deltaware. Although internal routers are not illegal, they are commonly used by heavily cybered (ie. dangerous) individuals and so likely to mark the user out for further investigation if openly displayed.
The smartlink is a headware module and software suite that offers an interface between the user’s nervous system and a smartgun. It can only function with DNI to the gun, although this can be wired or wireless.
It offers an advanced co-processor for realtime targeting calculation, 3d modelling of the environment built from the user’s senses, trajectory tracking for each round fired that feed back into the system to make future shots more accurate, and integration from the user’s nervous system into the targeting computation that automatically corrects for movement, hand microtremors, and body posture.
[^1] Reduced from 0.7 in RAW. [^2] No longer eyeware, as in RAW; smartlinks can only be implanted now, and not built into gear or into cybereyes.