My ISP, a state owned incumbent, buys bandwidth from different transit providers. Whenever it buys transits it announces only a specific prefix (in most cases a hitherto unused) through the new transit AS. For e.g. if it runs out of bandwidth, it buys bandwidth from a new transit and announces a new prefix through it, while the same prefix is not announced (or announced with lowest metrics, so that the routes are very rarely used) via the old transits which continue to provide bandwidth to it. I am a business customer, so I have a fiber based link to the ISP and a tiny subnet is given to me.
The subnet which is provide to me is part of a prefix which is announced by the AS of a transit who, it seems, do not have a presence in my country. So when I do a trace the packets, when they leave my ISP's AS, they take about 275ms to reach the transit providers core router, which is located in USA (half the world away). Also for upstream traffic my ISP uses a transit provider (tier 1) who has a presence in my country. But the return path is always through the transit which is in USA.
So, average latency is 400ms. All the users of other ISPs in my country discover my subnet via USA. Even the traffic from neighboring countries, from Europe (which is much nearer) follows the path via USA. Sites using CDNs also resolve to ips in USA.
I have informed the ISP NOC about the issue and I have asked them to provide an ip subnet belonging to a prefix announced by a local transit (preferably a tier 1 transit provider) and I am waiting for a reply. My question: Is it a serious issue that I must follow up to get it resolved? When I compared the latency on other providers in my country, it is, in most cases, less than half of my ISPs latency. Why my ISP doesn't announce all its prefixes to all of its transit providers, so that the packets can take efficient and nearest routes to reach prefixes that originate within its network?
