Chapter 162: Protocols and Broken Lines

The time in the lower-right corner of the screen flipped to two in the morning. In the dorm room, all that remained was the low hum of the computer fan and, now and then, the sound of freight trucks passing outside. Lin Chen stared at the stream of ConnectionRefused errors refreshing in the terminal. His fingers hovered over the keyboard, but he didn’t start typing right away.

He had checked the reconnection logic three times already. The exponential backoff algorithm, the TCP handshake retries, the resumable-transfer markers—none of them were the problem. The problem wasn’t in the script. It was in the environment. The internal network in Workshop No. 3 had been upgraded back in 2008; old industrial switches were now mixed together with newly installed behavior-management appliances, and some hidden security policy had most likely been triggered. He opened Wireshark, attached a packet capture filter, and reran the local simulation. The capture file popped up: a sea of red SYN_SENT packets, with no SYN-ACK replies coming back.

The gateway wasn’t down. The firewall was killing handshake packets on non-standard ports. The factory had updated its ACL rules just last week to protect against ransomware, allowing only ports 80 and 443. His script, by default, used port 502 for Modbus passthrough. It was being silently dropped.

Lin Chen rubbed his stinging eyes and created a new configuration file. He didn’t touch the core data-cleaning logic. Instead, he added a layer of protocol disguise: wrapping the industrial data stream inside HTTP POST requests, routing it outbound through port 443, then unpacking and restoring it in the cloud. The change added fewer than forty lines of code, but it bypassed the factory’s network blockade. Local testing passed. Latency dropped from 120 milliseconds to 45. He packaged the patch, attached deployment instructions, and sent it to Old Zhao.

Outside, the sky was turning gray-white. Lin Chen closed the laptop and lowered his head to look at his left foot. His ankle was swollen and shiny; the lining of his old leather shoe had already been worn through, and he couldn’t force his foot into it anymore. He dug out the pair of green canvas training shoes issued during freshman military drill. The uppers had yellowed, but the soles were soft. He pulled out two rolls of elastic bandage and wrapped them from his toes upward, locking the ankle in place, then yanked the laces tight. The instant the shoe cinched down, pain shot into his nerves like a fine needle. He inhaled sharply, but made no sound.

At 7:40, he left. Bus 312 to the factory was packed with workers heading for the early shift. The carriage smelled of soy milk, cheap tobacco, and sweat. He gripped the overhead rail and bore his weight on one leg as the bus swayed. Every jolt felt like stepping on broken glass with his left foot. He closed his eyes and reviewed the structure of the proposal in his head. What Professor Zhou wanted was not a technical manual, but industrial logic. He had to translate “the script runs fast” into “reduced production-line downtime,” and “low memory usage” into “compatible with aging industrial control computers, no hardware upgrade required.”

At nine sharp, he reached Workshop No. 3. The smell of machine oil mixed with the scorched-metal tang of cutting operations hit him head-on. Old Zhao stood in front of the control console with half a cigarette between his fingers, brow knotted.

“It’s connected.” Old Zhao pointed at the screen, where the data stream had started moving. “The network admin was cursing up a storm just now, swearing the policy hadn’t been changed. How the hell did your patch get around it?”

“It’s disguised as an HTTPS tunnel.” Lin Chen plugged his laptop into the workshop intranet and ran a full validation pass. “The logs are already flowing back. Disconnect rate is under two per thousand now. If the factory changes its policies again, the script will auto-detect the port and switch to a backup channel.”

Old Zhao exhaled a plume of smoke and ground the cigarette stub out on the side of a metal trash bin. “Next month the whole factory’s doing an asset inventory. More than thirty thousand devices. Piecework pay—eighty cents per item. You in or not?”

“I’m in.” Lin Chen’s voice was steady. “But we sign a settlement memo first. Data delivery counts only if cloud-side verification passes. Rework doesn’t get billed. Final payment settled monthly.”

Old Zhao looked at him for two seconds, then smiled. He rummaged through a drawer, pulled out a sheet of memo paper, wrote down the terms, signed it, and pressed his thumbprint onto it. “Fine. Kid, you’re starting to sound more and more like a businessman.”

Lin Chen tucked the note away without replying. He packed up his computer and turned to leave. His gait was still a limp, but his back was ramrod straight. Eighty cents each—thirty thousand entries made twenty-four thousand yuan. That money could fill the hardware gap in the proposal, and it could keep Xiaoman’s medicine from running out.

At one in the afternoon, he was back in the dorm. His roommate was out. A cup of instant noodles sat cold on the desk; he didn’t touch it. He opened his computer and created a new document: Provincial Department of Science and Technology Special Project Proposal_v2.1_Charts and Budget.

He opened Visio first and redrew the data-flow diagram. The messy hand-drawn boxes became a standard three-layer architecture: edge acquisition layer, protocol conversion layer, cloud storage layer. Next to each module, he annotated technical specifications and open-source dependencies. Then he revised the budget sheet. The commercial industrial gateway was cut and replaced with a Raspberry Pi 4B plus a self-developed ADC expansion board, bringing the cost down from eight thousand to twenty-six hundred. Sensors would come through the secondhand salvage market; he would solder the wiring himself, flash the firmware himself, and do the waterproof encapsulation himself. All the money saved would be shifted into server rental and reserved bandwidth funds.

The budget came down by eighteen percent—just enough to clear the threshold.

Under team responsibilities, he entered three names. He himself would handle core architecture and on-site debugging; Zhou Yu, a third-year computer science student who knew network protocols well, would handle edge-node networking; Li Rui, his classmate with solid Python fundamentals, would be responsible for data-labeling scripts and log monitoring. He opened WeChat and sent them both a message: Provincial Science and Technology special project. Need extra hands. Subsidy paid by hours worked. Progress check every Saturday afternoon at the library. Reply 1 if you can join.

Ten minutes later, two 1s popped up, one after the other.

Lin Chen proofread the materials word by word. Typos, punctuation, unit conversions—he checked them one by one. He replaced “multi-source heterogeneous data cleaning” with “edge-side data preprocessing based on lightweight containers,” and rewrote “automatic script retries” as “high-availability heartbeat detection and dynamic route switching.” The technical language was stripped of its rough, improvised edges and fitted into the frame of a policy document. This wasn’t packaging. It was a necessary act of translation for survival. He typed slowly. Under the desk, his left foot tapped lightly against the floor; the pain had already gone numb, fading into background noise. The glow of the screen cast a cold white light across his face. He made himself a bowl of noodles. Steam rose upward. He didn’t eat. He only watched the heat dissipate into the cold air.

At 11:47 that night, he clicked Send. The email progress bar reached 100 percent.

His phone vibrated. Professor Zhou had replied: Received. Before Friday's review meeting, prepare a 5-minute defense PPT. Focus on explaining clearly: why your team?

Lin Chen closed the laptop and leaned back in his chair. The dormitory’s fluorescent tube flickered once with a faint electrical buzz. He closed his eyes, and his breathing gradually steadied.

Then the screen lit up again. Incoming call: Qingshi Village Clinic.

He answered. His mother’s voice came through the static, carrying exhaustion she could not hide. “Xiaoman had another seizure last night. The doctor at the clinic said the domestic sodium valproate isn’t holding it anymore—we need to switch to the imported one. It’s forty yuan more per box, another hundred and twenty a month. Over there... is everything going smoothly for you?”

Lin Chen gripped the phone tighter, his knuckles whitening. “It’s going smoothly. I’ll transfer the money tomorrow. Don’t switch the medicine yet—let him keep taking the old one. I’ll come back Friday and take a look.”

“How’s your foot? Don’t push yourself too hard.”

“It’s much better. I’m hanging up.”

The call ended. The dorm room fell silent again. Lin Chen looked at the cover page of the proposal on the screen, the cursor resting in the field labeled “Projected Economic Benefits.” Wind had picked up outside, making the glass tremble softly. He knew that Friday’s defense would not be about how elegant the code was. It would be about whether this system could survive in the dirt. Investors cared about return rates. The science department cared about real-world deployment. He cared only about whether the numbers could be made to balance, whether the road could be opened.

He reopened the PPT template and created a new slide. In the title box he typed: From Workshop to Cloud: Field Validation of a Low-Cost Data Link

The night was still long.

But the road had already been laid beneath his feet.